# CVE-2026-11940

## Summary

- **CVE ID:** CVE-2026-11940
- **Severity:** HIGH
- **CVSS Score:** 7.8 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N)
- **CWE:** CWE-22, CWE-59
- **Published:** Jun 23, 2026
- **Last Modified:** Aug 13, 2026

## 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.

## Affected Products

- Python Software Foundation — CPython (0)
- Python Software Foundation — CPython (3.15.0a1)
- Python Software Foundation — CPython (3.14.0)
- Python Software Foundation — CPython (3.11.0)
- Python Software Foundation — CPython (3.12.0)
- Python Software Foundation — CPython (3.13.0)

## References

- [CNA](https://github.com/python/cpython/pull/151559)
- [CNA](https://mail.python.org/archives/list/security-announce@python.org/thread/LD6QIISNQFQYOIEPJNEUIPV7S3V76FZH/)
- [CNA](https://github.com/python/cpython/issues/151558)
- [CNA](https://github.com/python/cpython/commit/27dd970bf6b17ebca7c8ed486a40ab043ed7af8f)
- [CNA](https://github.com/python/cpython/commit/672825e2f36a57e173959b0d9d409d4560dab8df)
- [CNA](https://github.com/python/cpython/commit/771d12dda5140313db0ac550292987975651bbde)
- [CNA](https://github.com/python/cpython/commit/79c06bd5c6afa3c440d50faf7ee1b147c8832b4c)
- [CNA](https://github.com/python/cpython/commit/be13e86f6b9788a6f4d0419dffef72cbae5865c9)
- [CNA](https://github.com/python/cpython/commit/e5fdbd8d5aa923bd9111b112ea73bd6ec7c47877)
- [CNA](https://github.com/python/cpython/commit/0f852b3f07dd8e71e40326a51c02afbf16a42cc5)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.75%
- **EPSS Percentile:** 52.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._