What’s Vulnerable › Vulnerabilities

CVE-2026-4360: Tarfile.extract() doesn't fully respect filter parameter

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-30 · updated 2026-10-25
• Weakness: CWE-281

Description

In the Tarfile.extract() function, the filter parameter is not passed properly when extracting hardlinks. An affected system that extracts content from untrusted tar files could end up writing files with an unexpected uid/gid despite the user passing filter='data' to the extract() function.

Affected products

• Python: before 3.1.5 — fixed in 3.1.5

How to fix

Upgrade to a fixed version: Python 3.1.5. Check the vendor advisory for mitigations.

References

• https://github.com/python/cpython/commit/0367912be336348b30572f8029cec4a282782d92
• https://github.com/python/cpython/commit/5e0ef3f1afe892e4f64eb83368db57ac4c40cba0
• https://github.com/python/cpython/commit/7b57e8d51446297b8c7c482d224bc5f1938e4301
• https://github.com/python/cpython/commit/7ccdbaba2c54250a70d7f25632152df7655a5e0a
• https://github.com/python/cpython/commit/cf23b9153181062150d061468b6d24af33fe214f
• https://github.com/python/cpython/commit/d2b2f5eacab4dd48446b63340613b05dcbbf0b44
• https://github.com/python/cpython/commit/eee3ddf0ca10283cc7fea724aae9cd8665f8d15e
• https://github.com/python/cpython/issues/151987
• https://github.com/python/cpython/pull/151988
• https://mail.python.org/archives/list/security-announce@python.org/thread/TWZW2PC2AZOV6FENIHFSRC63OM7MBGSB/

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