CVE-2025-4330: high-severity vulnerability in Python Software Foundation CPython
Extraction filter bypass for linking outside extraction directory
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 1.0%
Allows the extraction filter to be ignored, allowing symlink targets to point outside the destination directory, and the modification of some file metadata.
You are affected by this vulnerability if using the tarfile module to extract untrusted tar archives using TarFile.extractall() or TarFile.extract() using the filter= parameter with a value of "data" or "tar". See the tarfile extraction filters documentation https://docs.python.org/3/library/tarfile.html#tarfile-extraction-filter for more information.
Note that for Python 3.14 or later the default value of filter= changed from "no filtering" to `"data", so if you are relying on this new default behavior then your usage is also affected.
Note that none of these vulnerabilities significantly affect the installation of source distributions which are tar archives as source distributions already allow arbitrary code execution during the build process. However when evaluating source distributions it's important to avoid installing source distributions with suspicious links.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Affected products
Python Software Foundation · CPythonRelated CVEs — Python Software Foundation CPython
In the same product, most dangerous first.
CVE-2024-7592HIGHQuadratic complexity parsing cookies with backslashesEPSS 2.3%CVE-2024-6232HIGHRegular-expression DoS when parsing TarFile headersEPSS 2.2%CVE-2024-12254HIGHUnbounded memory buffering in SelectorSocketTransport.writelines()EPSS 1.9%CVE-2025-13836MEDIUMExcessive read buffering DoS in http.clientEPSS 1.7%CVE-2025-0938MEDIUMURL parser allowed square brackets in domain namesEPSS 1.6%CVE-2025-4138HIGHBypassing extraction filter to create symlinks to arbitrary targets outside extraction directoryEPSS 1.5%
References
https://gist.github.com/sethmlarson/52398e33eff261329a0180ac1d54f42fhttps://github.com/python/cpython/commit/19de092debb3d7e832e5672cc2f7b788d35951dahttps://github.com/python/cpython/commit/28463dba112af719df1e8b0391c46787ad756dd9https://github.com/python/cpython/commit/3612d8f51741b11f36f8fb0494d79086bac9390ahttps://github.com/python/cpython/commit/4633f3f497b1ff70e4a35b6fe2c907cbe2d4cb2ehttps://github.com/python/cpython/commit/9c1110ef6652687d7c55f590f909720eddde965ahttps://github.com/python/cpython/commit/9e0ac76d96cf80b49055f6d6b9a6763fb9215c2ahttps://github.com/python/cpython/commit/aa9eb5f757ceff461e6e996f12c89e5d9b583b01https://github.com/python/cpython/commit/dd8f187d0746da151e0025c51680979ac5b4cfb1https://github.com/python/cpython/issues/135034https://github.com/python/cpython/pull/135037https://mail.python.org/archives/list/security-announce@python.org/thread/MAXIJJCUUMCL7ATZNDVEGGHUMQMUUKLG/