Description
nnU-Net is a semantic segmentation framework that automatically adapts its pipeline to a dataset. Prior to 2.4.1, the nnU-Net Issue Triage workflow in .github/workflows/issue-triage.yml is vulnerable to Agentic Workflow Injection. The workflow sets allowed_non_write_users: ${{ github.event.issue.user.login }}, which means any logged-in GitHub user who opens an issue can reach this agentic workflow with attacker-controlled content. Untrusted issue title and body content are embedded directly into the prompt of anthropics/claude-code-action, and the workflow then runs a command-capable Claude agent with permission to comment on and relabel the current issue via gh. Because this workflow is triggered automatically on issues.opened, an external attacker can submit a crafted issue that steers the agent beyond its intended issue-triage purpose and influences authenticated issue actions. This vulnerability is fixed in 2.4.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| MIC-DKFZ | nnUNet | < 2.4.1 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 2 repositories
-
sushant-me/agentic-workflow-injection ★ 0 · Sep 16, 2026
Reproducible vulnerable/fixed fixtures for agentic workflow injection in GitHub Actions (CVE-2026-44246), plus measured detector coverage
-
pvharmo2/gha-lab-733c168b88 ★ 0 · Sep 6, 2026
Authorized security-research lab reproducing CVE-2026-44246 (GHSA-63mx-j37w-gh59): prompt injection via verbatim issue title/body inlining into the claude-code-action triage agent in nnU-Net's issue-…
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.