What’s Vulnerable › Vulnerabilities

CVE-2025-4435: Tarfile extracts filtered members when errorlevel=0

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-06-03 · updated 2026-07-31
• Weakness: CWE-682

Description

When using a TarFile.errorlevel = 0 and extracting with a filter the documented behavior is that any filtered members would be skipped and not extracted. However the actual behavior of TarFile.errorlevel = 0 in affected versions is that the member would still be extracted and not skipped.

Affected products

• Python: before 3.9.23; from 3.10.0 before 3.10.18; from 3.11.0 before 3.11.13; from 3.12.0 before 3.12.11; from 3.13.0 before 3.13.4; from 3.14.0a1 before 3.14.0b3 — fixed in 3.10.18, 3.11.13, 3.12.11, 3.13.4, 3.14.0b3, 3.9.23

How to fix

Upgrade to a fixed version: Python 3.10.18, 3.11.13, 3.12.11, 3.13.4. Check the vendor advisory for mitigations.

References

• https://github.com/python/cpython/commit/19de092debb3d7e832e5672cc2f7b788d35951da
• https://github.com/python/cpython/commit/28463dba112af719df1e8b0391c46787ad756dd9
• https://github.com/python/cpython/commit/3612d8f51741b11f36f8fb0494d79086bac9390a
• https://github.com/python/cpython/commit/4633f3f497b1ff70e4a35b6fe2c907cbe2d4cb2e
• https://github.com/python/cpython/commit/9c1110ef6652687d7c55f590f909720eddde965a
• https://github.com/python/cpython/commit/9e0ac76d96cf80b49055f6d6b9a6763fb9215c2a
• https://github.com/python/cpython/commit/aa9eb5f757ceff461e6e996f12c89e5d9b583b01
• https://github.com/python/cpython/commit/dd8f187d0746da151e0025c51680979ac5b4cfb1
• https://github.com/python/cpython/issues/135034
• https://github.com/python/cpython/pull/135037
• https://mail.python.org/archives/list/security-announce@python.org/thread/MAXIJJCUUMCL7ATZNDVEGGHUMQMUUKLG/

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