CVE-2025-8194

Description

There is a defect in the CPython “tarfile” module affecting the “TarFile” extraction and entry enumeration APIs. The tar implementation would process tar archives with negative offsets without error, resulting in an infinite loop and deadlock during the parsing of maliciously crafted tar archives. This vulnerability can be mitigated by including the following patch after importing the “tarfile” module: import tarfile def _block_patched(self, count):     if count < 0: # pragma: no cover         raise tarfile.InvalidHeaderError("invalid offset")     return _block_patched._orig_block(self, count) _block_patched._orig_block = tarfile.TarInfo._block tarfile.TarInfo._block = _block_patched

Reserved 2025-07-25 | Published 2025-07-28 | Updated 2025-07-28 | Assigner PSF

Problem types

CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')

Product status

Default status
unaffected

Any version before 3.14.0
affected

Credits

Alexander Urieles reporter

Seth Larson coordinator

Ethan Furman remediation reviewer

Steve Dower remediation reviewer

References

github.com/python/cpython/issues/130577 issue-tracking

github.com/python/cpython/pull/137027 patch

mail.python.org/.../thread/ZULLF3IZ726XP5EY7XJ7YIN3K5MDYR2D/ vendor-advisory

github.com/...ommit/7040aa54f14676938970e10c5f74ea93cd56aa38 patch

github.com/...ommit/cdae923ffe187d6ef916c0f665a31249619193fe patch

cve.org (CVE-2025-8194)

nvd.nist.gov (CVE-2025-8194)

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