Vulnerability in nnU-Net (CVE-2026-44246)
Summary
Vulnerability in nnU-Net (CVE-2026-44246). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.4.1 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-44246 has been found in nnU-Net.
Risk of unauthorized operations or information disclosure. CVSS score: 7.2/10.
What to do: upgrade nnU-Net to 2.4.1 or later.
If unsure, ask your IT team or search "nnU-Net CVE-2026-44246" on the vendor's site.
CVE-2026-44246 (nnU-Net) — CWE-74 / CVSS v3 7.2
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 2.4.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-74) exists in nnU-Net.
Check the vendor advisory for the affected versions of nnU-Net.
Severity: High (CVSS 7.2/10). Risk of unauthorized operations or information disclosure.
Update to 2.4.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'nnU-Net' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'nnU-Net' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
nnU-Netを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade nnU-Net to 2.4.1ステージング環境で 2.4.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov