CVE-2026-11940
tarfile.extractall() with the 'data' or 'tar' filter could be bypassed by a crafted archive where a hardlink references a symlink stored at a deeper name than the hardlink itself. …
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
tarfile.extractall() with the 'data' or 'tar' filter could be bypassed by a crafted archive where a hardlink references a symlink stored at a deeper name than the hardlink itself. The extraction fallback validated the symlink at it's archived location but recreated it at the hardlink's shallower path, letting a relative target the filter judged contained escape the destination directory. This allowed a malicious tar archive to create a symlink pointing outside the destination, enabling out-of-destination file reads or writes. This was an incomplete fix of CVE-2025-4330.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-11940 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-11940 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-11940. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-11940 in your dependencies?
O3 detects CVE-2026-11940 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.