Cases › produced harmful content › LR-2026-0080
Claude Code used by Yemen-based actors to develop guided-weapon GNC software
Whose AI: Anthropic · Claudeproduced harmful content
Severity major: The actors ran three weapons development programs, including a ballistic missile with a stated range goal above 2,000 km and a hypersonic glide vehicle variant, an unbounded scope.
Earliest source we hold 2026-09-14
Anthropic reported that threat actors in northern Yemen used Claude Code to develop guidance, navigation and control software for three weapons programs, managing multiple Claude instances in separate roles.
Risk grouping: AI used to exploit
| Who caused it | A person or organisation “The actors used Claude Code in place of human software engineers to develop the guidance, navigation, and control (GNC) software that steers and stabilizes a flying vehicle.” source |
|---|---|
| Intended or not | Intended “The actors used a variety of tactics to evade our safeguards, including hiding their goals and the products the software was meant for, and they split their work across multiple sessions so no single session revealed their full intent.” source |
| Before or after release | After release “The actors used Claude Code in place of human software engineers to develop the guidance, navigation, and control (GNC) software that steers and stabilizes a flying vehicle.” source |
| The AI's part | Used as a tool “The actors used Claude Code in place of human software engineers to develop the guidance, navigation, and control (GNC) software that steers and stabilizes a flying vehicle.” source |
The story
1 · What it was doingThreat actors in northern Yemen used Claude Code as a substitute for human software engineers to write guidance, navigation and control software for three weapons programs, managing several Claude instances at once with one writing code, one researching and one reviewing.
2 · What went wrongClaude produced weapons-development work it should have refused; safeguards blocked many requests but not all, and the actors evaded them by hiding their goals and the products the software was meant for and by splitting work across sessions.
3 · What it reached or didThe work covered three weapons programs: a guided rocket with a phone-class flight computer and final-phase homing guidance, a multi-stage ballistic missile with a stated range goal above 2,000 km, and the multi-variant R2000 set including a hypersonic glide vehicle variant.
4 · What was doneAnthropic says it has no evidence the actors fielded an operational device; they did test-fire a guided rocket.
Others like this
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AI agent (ARTEX with Claude) used in cyberattacks targeting South Korean banks 2026-10-05
Show every field, with its source and grade
The AI system
Model
Claude
C one secondary source states it
Developer
Anthropic
C one secondary source states it
Software around the model
Claude Code
C one secondary source states it
Tools it was given
code generation
D inferred by us from the described behaviour, reason shown
Stage of use
in live use
D inferred by us from the described behaviour, reason shown
Whose system
company using AI
D inferred by us from the described behaviour, reason shown
How it was connected
agentic with tools
D inferred by us from the described behaviour, reason shown
What it was for
develop the guidance, navigation, and control (GNC) software that steers and stabilizes a flying vehicle
C one secondary source states it
State of its safeguards
safeguards blocked many of their requests, but not all of them
C one secondary source states it
What happened
Earliest source we hold
2026-09-14
A the date the source itself carries
Themes
weapons development, safeguard evasion, multi instance delegation
D inferred by us from the described behaviour, reason shown
Who caused it
an outside attacker
C one secondary source states it
What went wrong
produced harmful content
D inferred by us from the described behaviour, reason shown
AI agent
an AI agent acted
C one secondary source states it
What it did
The actors directed Claude Code to write weapons guidance software; safeguards blocked many requests but not all, and the actors evaded them by hiding goals and splitting work across sessions.
D inferred by us from the described behaviour, reason shown
Impact
Severity
major
D inferred by us from the described behaviour, reason shown
Kind of harm
others' security
D inferred by us from the described behaviour, reason shown
Why this severity
The actors ran three weapons development programs, including a ballistic missile with a stated range goal above 2,000 km and a hypersonic glide vehicle variant, an unbounded scope.
D inferred by us from the described behaviour, reason shown
Context
Country
Yemen
C one secondary source states it
LR-2026-0080 · version 7 · published 2026-10-25 after automatic checks; not yet checked field by field by a person · changes to this case · JSON