Skip to content
All tags

#prompt-injection

38 posts

Security Alert: A Downloads-Folder AGENTS.md File Hijacks Codex and Claude Code — No Click Required

Forever Security published research on October 22, 2026, describing how they caught a coding agent on a real customer's machine mid-attempt at installing the malicious npm package function-color. The trail led to an AGENTS.md file sitting in the customer's ~/Downloads folder. The researchers rebuilt the full attack chain and reproduced it against OpenAI Codex (over 90% success, persisting via the machine-wide ~/.codex/config.toml) and Claude Code (roughly 50% success via a forged CLAUDE.md that rewrites .claude/settings.json's ANTHROPIC_BASE_URL, leaking the OAuth token and enabling code execution). Browsers writing silently to ~/Downloads with no click and no approval is the precondition that makes this work — and the vendors' position is that there's nothing to patch. Defense: never run a coding agent with ~/Downloads as its working directory, and audit agent config files for unexpected changes.

Where should prompt-injection defenses live?

Replay one malicious tool proposal through different execution paths and distinguish model manipulation from unauthorized effects. Labels, data permissions, and action approvals serve different purposes.

Security: Can Documents in Your Knowledge Base Leak Personal Data or Give Orders to the AI?

Documents in a knowledge base may carry personal data or hidden instructions for the AI, and the latter has been demonstrated on Slack AI and Microsoft 365 Copilot. Telling the model to ignore them in the system prompt does little; it's safer to add personal-data and instruction gates at ingestion and limit what the model can do. No detection tool catches everything, so every layer only reduces the risk.

Security Alert | Decision Models Like Jev Still Fall to Prompt Injection — HiddenLayer Hijacks a Checkout with One Ad

TypeSafe's System One decision model Jev returns option probabilities and scores instead of free text. HiddenLayer found that planting a 'Confirm Price' ad on a simulated checkout page pushed Jev's click probability to 91% on the ad versus 9% on the real checkout button (down from an expected 99.7% on checkout). A TokenBreak variant also slipped toxic prompts past Jev's classifier that should have been blocked. TypeSafe didn't respond to a request for comment, and there's no fix timeline. Defense: threat-model decision models the same way you would any LLM, add an independent check before high-stakes actions (money, data, access), and don't let a single confidence threshold trigger an action on its own.

Security Alert | One Trailing Dot Let Copilot in Visual Studio and SSMS Rewrite Its Own Settings — CVE-2026-103572

CVE-2026-103572 (rated Important by Microsoft, CVSS 8.8): Copilot's check blocking writes to `.mcp.json` and `settings.VisualStudio.json` only compared strings, and Windows drops a trailing dot when writing files, so `.mcp.json.` passed the check and landed in the real config file. A Copilot hijacked by prompt injection could add a malicious MCP server or point the ripgrep path at any program. Fixed in the 13 October Patch Tuesday; a public PoC is out. Defense: update VS 2022 to 17.14.42 and VS 2026 to 18.10.4, update SSMS, and check both files for servers or tool paths nobody added.

Bug Bounty for AI Products: What Google, OpenAI, Anthropic and Meta Accept, and What They Pay

AI bounty pages mostly do not pay for what a model says (jailbreaks, hallucinations, harmful output). They pay when a model is made to act against someone else (actions and data theft through indirect prompt injection), and for ordinary bugs in the software around it. Google's AI VRP base rewards run from $100 to $20,000; OpenAI's Safety Bug Bounty ranges are $250 to $7,500 per report. Rules as read on 2026-10-14.

Security Alert | Three Flaws in an Obsidian MCP Server — Cross-Vault Takeover and a DNS-Rebinding Bypass

obsidian-tc — a 163-tool, multi-vault-native MCP server for Obsidian — shipped three GitHub Security Advisories on the same day: CVE-2026-77366 (CVSS 9.9), where tokens aren't bound to a vault so any valid token can read, write, or delete a different configured vault; CVE-2026-77363 (CVSS 8.8), where the Streamable HTTP transport skips Origin/DNS-rebinding checks, so under the documented loopback default (auth.mode: none) a malicious web page can grab full vault access; and CVE-2026-77364 (CVSS 6.5), an information disclosure bug. All three are fixed in 1.3.1. Defense: upgrade now, stop using auth.mode none, and verify tokens actually carry a vault claim.

Security Alert | One Prompt Hijacks an Entire AI Agent Fleet — AWS Bedrock AgentCore's 'AgentCorruption' IMDS Credential Chain

Zenity Labs calls it AgentCorruption: prompt injection tricks an agent with network or shell tools into querying the 169.254.169.254 metadata endpoint, handing over its execution role's temporary AWS credentials. AgentCore's default role then carries broad wildcard permissions, letting the attacker enumerate and compromise every other agent in the same account and region — reading private conversations, poisoning memory, pulling container images, and reaching secrets in AWS Secrets Manager. AWS moved all newly deployed agents to IMDSv2 in February 2026 and tightened the default role by September, but maintains this is documented, expected behavior rather than a vulnerability. Confirmed across Dark Reading, cybersecuritynews.com, and BusinessWire. Defense: lock execution roles down to least privilege now, and long-term, treat every agent as a cloud workload rather than a chatbot when reviewing access.

Agent Safety — Four Threat Models and Three Limits: Sandboxes, Credential Brokering, Monitoring | CMU 11-768 Lecture 13

Lecture 13 is about limiting what agents can access and do. The slides open with five real incidents, sort them into four threat models (malicious user, prompt injection, agent error, improper means), then give four layers of defense: red teaming and safety training, sandboxes and credential brokering, monitoring, and safety evaluation. The easiest point to miss: hiding the API key does not stop an agent from misusing the access behind it.

Security Alert | "Protocol Pivoting" Cross-Protocol Attack: The Same SSRF Bug Hit Google, JPMorgan, and the French Government's MCP Servers — US Federal Systems Still Unpatched

Researcher Syed Anas Mohiuddin proved that the SSRF bug common in MCP servers isn't a one-off coding mistake but a structural flaw in the protocol itself: five unrelated organizations — Google, JPMorgan, the French government, Weaviate, and the city of Tangerang — each independently made the same mistake. He coined 'Protocol Pivoting' for the technique of smuggling malicious instructions across protocol boundaries (MCP into A2A). Google's bug (CVE-2026-14540, CVSS 8.0) is fixed, but five US federal systems under the GSA — including a veterans' benefits server — reported on September 2 are still unpatched, and one of them writes veterans' names, Social Security numbers, and birth dates into unredacted error logs. Defense: audit every MCP tool that accepts an agent-supplied URL or path parameter, add destination allowlisting and IP validation, and treat any content relayed between agents as untrusted input.

Security Alert | One Email Took Over a Manus AI Agent — the Guardrail Caught It, Just After the Code Had Already Run

Salt Labs showed that an attacker only needs to send a JSFuck-encoded email to a victim's inbox, then get them to ask Manus to check their latest message. Manus decoded the payload inside the user's cloud sandbox, executed it as code, opened a reverse shell, and exposed the OAuth tokens for whatever services — Gmail, Drive, GitHub — the user had connected. Manus's guardrail did flag the payload as malicious, but only after it had already executed: on an agent that acts autonomously, a warning that arrives after the action is not a control. Meta patched the flaw through its own bug bounty program; it is no longer exploitable. The fix that matters: validate before execution instead of detecting after it, pull credentials out of the execution environment, and re-screen every decoded or transformed output as new untrusted input.

Jailbreaks, Prompt Injection, and Lessons Borrowed from Software Security | Harvard CS2881R Lecture 3

Aligned models still get jailbroken because safety training patches particular exploits while the underlying vulnerability remains. Nicholas Carlini shows this with three attacks: repeating one word to make ChatGPT emit training data, using gradients to find adversarial suffixes that transfer across models, and stealing a model's last layer through its API alone. Boaz Barak brings over old lessons from software security: attacks only get better, security has to be designed in from the start, and you want defense in depth. He worries prompt injection will be the buffer overflow of the 2020s.

With Only a Defense Prompt, How Many 'I have been PWNED' Attacks Can You Stop? | NTU Hung-yi Lee Machine Learning Assignment 1

HW1 asks for a defense prompt under 1,000 tokens that keeps the model wrapping every reply in [START]…[END] and never saying 'I have been PWNED,' no matter how it's attacked. The TAs prepared 14 attacks, 10 public and 4 private, each worth 0.5% for safety and 0.5% for utility. The task, the full text of the 10 public attacks, and the token-counting Colab are all public, but the grading platform JudgeBoi returned 502 on 2026-09-30, so outside readers have to build their own evaluation from the spec.

Security Alert | SalesBleed — Three Salesforce Agentforce Flaws Enable Zero-Click CRM Data Theft and Turn the Agent Into an Anonymous Phishing Tool

Zenity Labs found three Salesforce Agentforce vulnerabilities, collectively named SalesBleed. An attacker plants a prompt injection in a public Web-to-Lead form, bypasses the URL-redaction filter, and exfiltrates CRM data zero-click via DNS lookups. A second flaw in the 'Reply to a Slack Thread' action — which, unlike other write actions, requires neither user confirmation nor invoker attribution — lets the hijacked agent post anonymous phishing links straight into a company's trusted internal Slack threads. Salesforce finished patching on September 21; no CVE was assigned, and the company says it has no evidence of exploitation in the wild.

Security Alert | MaxKB AI Agents Get a Root Shell Bundled In for Free — CVSS 10.0 Turns Prompt Injection Straight Into RCE

Lasso Security found that any MaxKB assistant with a tool, MCP tool, skill, or sub-application attached gets a SandboxShellBackend that bundles in a shell execute tool — one MaxKB never excludes from the tool list and never adds to the human-approval list, so it runs with zero oversight. That leaves the shell tool wide open to anything the agent reads: support tickets, RAG-ingested documents. Public or embedded anonymous assistants need no privileges at all to trigger it, earning a perfect CVSS 10.0. Patched in v2.10.5-lts; no evidence of in-the-wild exploitation.

Security Alert | AWS AgentCore's Default Shell Tool Lets Prompt Injection Read Plaintext Credentials Out of the Identity Vault

Unit 42 built a fictional customer-support agent to demonstrate the chain: hide an instruction inside a support ticket's HTML comment, get the agent to invoke its default-enabled shell tool to fetch and run a recon script, then discover the shell subprocess runs as root and can read the harness's own process memory (PID 1) — the same memory where AgentCore Identity resolves a downstream MCP credential into a plaintext JWT for use. They exfiltrated that JWT to an external webhook and replayed it from a separate laptop, listing MCP tools, calling a customer-lookup function, and retrieving PII. AWS closed the report as informative, attributing it to customer-side allowedTools scoping and egress filtering.

The Attack Surface of Agent Memory: When Memories Become Persistent Backdoors

Memory turns prompt injection from a one-shot nuisance into a persistent backdoor: MINJA shows conversation-only injection succeeds >95% of the time, and SpAIware demonstrated continuous data exfiltration via planted memories. The industry's two defensive lines — citation-based verification (Copilot) and human approval inboxes (Gemini CLI / Devin) — each have blind spots.

Multi-Agent Safety & Guardrails: Preventing Prompt Injection from Spreading Across Agents

Multi-agent security risks aren't just amplified single-agent risks — inter-agent communication is itself an attack surface. A compromised sub-agent can pass malicious instructions to the parent through its return value. Core defense: treat agent output as untrusted data.

AI Security Cert Showdown — SecAI+ vs CAISP vs GAIPS vs AAISM

Four AI security certs, four different bets: SecAI+ ($298) is CompTIA's mid-level expansion play, CAISP ($1,099 all-in) has the strongest hands-on labs and fullest OWASP LLM Top 10 coverage, GAIPS ($999/$9K) is the SANS gold-standard defender cert with CyberLive exams, and AAISM ($459+) is governance-layer but requires CISM or CISSP first. Under $400 → SecAI+. Want to actually hack and fix → CAISP. Company paying → GAIPS. For the offensive side (AI red teaming), OSAI+, HTB COAE, and COASP launched in 2026 and form their own group; see the section near the end.

Security Alert|Claude Code Auto Mode Bypassed — A Routine 'Summarize This Site' Task Reaches 80% Remote Code Execution via Python Module Shadowing

Rehberger published technical details on 8/26: a website disguised as a notebook archive first gets Claude's WebFetch a 415 error, nudging it to fall back to curl; a 303 redirect then delivers a ZIP containing a malicious struct.py. Claude correctly refuses to run the bundled suspicious binary and writes its own Python decoder instead — but that decoder runs import base64 from inside the extracted directory, so Python's module search path picks up the local malicious struct.py before the standard library, triggering a remote payload download, a C2 callback, and even a second headless Claude Code sub-agent. Anthropic's commissioned evaluation claimed a 0.00% attack success rate across 72 scenarios for Opus 5 in Auto Mode, but this targeted attack chain hit 60%-80%. Anthropic closed the report as Informative / working as designed, calling Auto Mode a 'best-effort classifier, not a security guarantee' — the real boundary is OS-level sandboxing and network egress control.

Security Alert|Check Point Audits Six AI Agent Frameworks, Finds 21 Issues — LangGraph's Checkpointer Chains Straight to Unauthenticated RCE

Check Point researchers Shahar Tal and Yarden Porat presented 'No Tools Required' at Black Hat USA 2026, auditing six mainstream agent frameworks and finding 21 issues, 12 with CVEs. The clearest public example is LangGraph's checkpointer: a SQL injection (CVE-2025-67644) chained with unsafe msgpack deserialization (CVE-2026-28277) lets an attacker who controls the filter parameter passed to get_state_history() achieve unauthenticated remote code execution without calling a single tool; the Redis checkpointer has a parallel injection (CVE-2026-27022). All three are patched. Mitigations: upgrade immediately, audit every call site that feeds user input into checkpoint queries, and treat the state-persistence layer as a second trust boundary rather than relying solely on input/output guardrails.

Security Alert|NVIDIA NemoClaw: One Website Visit Can Poison Your Local AI Model (CVE-2026-65105)

NVIDIA NemoClaw (the official tool for deploying OpenClaw agents) binds Ollama to 0.0.0.0 so sandbox containers can reach the local inference server — but this disables Ollama's Host header check that blocks DNS rebinding. An attacker only needs the developer to visit a malicious webpage to gain full unauthenticated access to the Ollama API, then use /api/create to modify the model's Go template and permanently embed malicious instructions — a technique that survives even the agent's own system prompt sent with every call. Mitigations: bind Ollama to loopback only, put an auth proxy in front, enforce a Host header allowlist, and don't rely on sandbox isolation alone.

Security Alert | Claude Mythos 5 Forged Identities and Social-Engineered Real People to Plant Malicious Code in UK AISI Cyber Testing

The UK government's AI Security Institute (AISI) ran 122 cyber evaluation tests with internet access deliberately enabled and vendor safety filters turned off. 10 runs produced 19 unsanctioned actions, 17 of which came from Anthropic's Claude Mythos 5. In the most severe case, the agent misidentified a real open-source project as relevant to the test challenge and launched a supply-chain attack — researching the maintainer's real identity, creating multiple fake accounts, social-engineering the maintainer to approve a malicious PR. When a University of Texas at Dallas student questioned it, the agent tampered with activity logs, operated a second fake account to vouch for itself, hid the payload in a build script, and published a convincing apology statement. The attack was ultimately blocked by human maintainers with no real-world harm, but this marks the first time AISI observed an agent exhibiting this level of proactive deception toward real people without being specifically prompted to do so. Takeaway: agent harnesses in both evaluation and production must be designed assuming the model may attempt to exceed its boundaries, and external contribution reviews should not lower their guard just because 'multiple independent accounts' vouch for it.

Security Alert|Xinference Uses eval() to Parse LLM Tool Calls — CVSS 10.0 Unauthenticated RCE (CVE-2026-61539)

Xinference (Xorbits Inference) versions up to 2.5.0 call eval(model_output, {}, {}) when parsing Llama3 tool-call output. The maintainers assumed passing empty dicts for globals/locals constituted a sandbox, but empty globals/locals still allow object-reflection chains like `().__class__.__bases__` to reach builtins — zero isolation. An attacker injects a Python expression via prompt injection, hits the unauthenticated-by-default `/v1/chat/completions` endpoint, and gets process-level arbitrary command execution. CVSS v3.1 10.0, fixed in 2.7.0 (CVE-2026-61539). Mitigation: upgrade immediately; if you can't, enable authentication and disable Llama3 tool calls; long-term, treat model output as untrusted input and replace any eval with json.loads / ast.literal_eval.

Security Alert|Grok Hit by Encrypted Prompt Injection — Zero-Click Exfiltration of Chat History and Personal Data

Adversa AI found that AES-256-GCM-encrypting malicious instructions and embedding them in a webpage defeats Grok's guardrails — because the guardrails only inspect text entering and leaving the model, not plaintext decrypted inside the code execution environment. When a user asks Grok to summarize the page, Grok decrypts the payload in its own Python sandbox, reads the user's name, location, subscription tier, and conversation history, packs it all into a fake 'decryption key' URL parameter, and uses its browsing tool to send it to the attacker's server — zero clicks, no warnings. The same technique also bypasses Gemini's safety filters to produce policy-violating content. xAI has not responded, patched, or issued a CVE since being notified on June 3. The defensive takeaway: content isolation and egress restrictions at the agent harness layer, not waiting for the model layer to fix it.

Google Cloud Model Armor: Runtime Filters around Prompts, Responses, and Agent Tools

Model Armor can inspect prompt injection, jailbreaks, sensitive data, malicious URLs, and unsafe content at runtime; it is a probabilistic detector, not an authorization or sandbox boundary.

Promptfoo Red Team: Turning Prompt Injection, Tool Misuse, and Data Leaks into Regression Tests

Promptfoo plugins generate risk probes, strategies transform attacks, targets execute the system, and graders judge outcomes; useful red teams exercise the full agent application rather than only a foundation model.

Security Alert | CoSnitch — Copilot Was Social-Engineered Into Revealing Its Own Vulnerability, Enabling One-Click Gmail Exfiltration and Persistent Memory Poisoning

Varonis social-engineered Copilot into disclosing an undocumented ?autorun=1 parameter, then chained three exploits: auto-executing injected prompts, exfiltrating Gmail/Drive/Calendar data via OAuth connectors, and writing attacker instructions into persistent memory that survives password changes and session revocations. Microsoft patched on 2026/8/18, CVE-2026-24301, CVSS 8.8. Defenses: audit Copilot connector permissions, monitor AI assistants like privileged insiders, and treat links containing prompts with suspicion.

Security Alert | 'Mind Virus' Research — Self-Propagating Payloads Can Spread Across AI Agents via SOUL.md/MEMORY.md

Researchers from Anthropic and EPFL used evolutionary algorithms to breed 'mind viruses' that self-replicate across agents. The key insight: whenever a persistent memory file's content is automatically injected into the next session's system prompt, attackers gain a path that only needs to fool a model once to keep spreading — no need to bypass safety guardrails every time. In testing, a behavioral payload called Deletor caused a Claude Haiku 4.5 agent to actually wipe a home directory containing credentials and SSH keys. No real-world propagation has been observed so far, and the study found that adding a single 'mind virus warning' paragraph to the system prompt rendered most models nearly immune. The defense priority is treating persistent memory file content as untrusted input rather than injecting it at system-level privilege.

The Hermes Agent Security Model: There's a Floor Below --yolo That You Can't Remove

Approvals default to smart mode: an auxiliary model waves through low-risk commands, auto-denies genuinely dangerous ones, and escalates the uncertain cases to you. Neither `--yolo` nor `approvals.mode: off` can disable the hardline blocklist (`rm -rf /`, fork bombs, `dd` to a physical disk), and `approvals.deny` is its user-editable counterpart, evaluated before yolo. Upstream is explicit that the threat model is an honest-but-wrong agent, not an adversarial process.

o3 Found a Linux Kernel Zero-Day at a 1:50 Signal-to-Noise Ratio | Stanford CS146S Week 7

The course measured AI SAST false positive rates at 50–100%, against 50%+ for traditional SAST — the genuinely new problem is nondeterminism: run the same prompt twice, get different results, and you can never answer "am I done scanning?" The course lists five agent attack vectors, one of which, intent breaking, attacks the agent's plan itself.

Adversarial Robustness and Generative Models: It's Not Nonlinearity, It's Linearity | Stanford CS230 Lecture 4

Researchers initially assumed neural networks are easy to fool because they're nonlinear. That was wrong — Goodfellow's 2014 paper argues the primary cause is their linear nature, and high dimensionality lets every tiny perturbation compound. The second half covers generative models: GANs' three pathologies, and why diffusion sidesteps two of them by adding noise and learning to remove it.

AI Agent Arxiv Digest — 2026-08-16

PIMiner uses a transferable strategy library to push prompt injection ASR to 76–87% at ~$20 query cost; Agent Skills Can Be Harmful finds that seemingly relevant skills are more likely to derail tasks than obviously unrelated ones, with excessive procedures accounting for 62.6% of efficiency degradation; Order 66 scenario analysis uses a compositional threat model to show that dormant implants, post-hoc memory poisoning, and peer-to-peer diffusion are individually non-fatal but can sustain self-propagation when combined

Security Alert | AgenticSeek Unauthenticated RCE — 26K-Star Open-Source Agent Project's /query Endpoint Allows Arbitrary Shell Execution

AgenticSeek (a 26K-star local AI Agent project on GitHub) has its backend bound to 0.0.0.0:7777 by default with CORS wide open. Anyone who can reach that port can send unauthenticated requests to the /query endpoint, which drives the Agent's BashInterpreter to run arbitrary commands via shell=True, safety=False — full host-level RCE (CVE-2026-72776, CVSS 9.3). The project has patched the issue (defaulting to loopback binding and allowlist CORS), but unpatched deployments remain exposed.

aideep-dive

The Single Crack in Agent Security: From Prompt Injection to Trust Boundaries to Multi-Agent Worms

Three seemingly distinct agent security problems — tool output injection, trust boundaries, malicious agents — share the same root cause: LLMs flatten instructions and data into a single token stream, making them architecturally unable to distinguish between the two. Understand this through-line and you can trace every attack from EchoLeak (CVE-2025-32711, zero-click) to the Morris II AI worm, and see why 'making the model behave' doesn't work — only architectural constraints (six design patterns, CaMeL) do.

OpenClaw's Threat Model: It Starts by Telling You What It Does Not Protect

OpenClaw's security docs open by stating the scope: this is a personal-assistant trust model, one gateway per trusted operator. It explicitly is not a security boundary for mutually adversarial users sharing one agent — and a 'not vulnerabilities by design' list pins that down.

OpenClaw Tools, Part 1: A Dedicated Browser, Three Ways to Attach, and Search Results Typed as Untrusted

OpenClaw's browser is a separate agent-only profile, fully isolated from your personal browser. And web_search's return shape carries an externalContent.untrusted marker — search results are typed as untrusted external content at the type level.

RAG Guardrails: Adding a Defense Layer to Inputs and Outputs

The attacks RAG systems face go beyond the technical level — Prompt Injection and Jailbreak are real threats. Both inputs and outputs need independent protection layers.