Home / Incidents / STUPID-2026-0030
STUPID-2026-003010.0criticalClineVerified

Clinejection: an AI issue-triage workflow enabled arbitrary code execution on the CI runner

10/10
Severity
Security Vulnerability
Failure Mode
Reproducible
No
Date
February 15, 2026

Expected Behavior

Treat issue text from arbitrary users as untrusted input; never let it drive privileged actions or command execution on the runner.

What Actually Happened

Cline's AI-powered issue-triage workflow fed untrusted issue content to an agent that could act on it, allowing a crafted issue to achieve arbitrary code execution on the CI runner with access to the workflow's secrets.

Damage Assessment

Because the workflow ran in CI with repository secrets in scope, a single malicious issue could reach credentials and tokens — multiplying the blast radius of a prompt-injection into a supply-chain risk.

Full Report

The 'Clinejection' incident, disclosed in February 2026, showed how AI agents wired into CI/CD multiply risk. Cline had added an AI-powered issue-triage workflow in December 2025 that used an automated code action to respond to GitHub issues. Because issue text comes from arbitrary, untrusted users, a crafted issue could inject instructions that drove arbitrary code execution on the runner — with access to whatever secrets and credentials the workflow held. It is a canonical example of prompt injection escalating into a supply-chain problem the moment an agent is given the ability to act on untrusted input in a privileged environment.

Incident Metadata

Agent
Cline
Failure Mode
Security Vulnerability
Root Cause
Tool Misuse
Task Type
deploy
Domain
infra
Source
news_report
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