Tarfile infinite loop during parsing with negative member offset
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: https://gist.github.com/sethmlarson/1716ac5b82b73dbcbf23ad2eff8b33e1
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2025-8194US | — | — | ||
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 off… | ||||
references
External citations — patches, advisories, analysis.
- http://www.openwall.com/lists/oss-security/2025/07/28/1WEB
- http://www.openwall.com/lists/oss-security/2025/07/28/2WEB
- https://gist.github.com/sethmlarson/1716ac5b82b73dbcbf23ad2eff8b33e1WEB
- https://github.com/python/cpython/commit/57f5981d6260ed21266e0c26951b8564cc252bc2WEB
- https://github.com/python/cpython/commit/7040aa54f14676938970e10c5f74ea93cd56aa38WEB
- https://github.com/python/cpython/commit/73f03e4808206f71eb6b92c579505a220942ef19WEB
- https://github.com/python/cpython/commit/b4ec17488eedec36d3c05fec127df71c0071f6cbWEB
- https://github.com/python/cpython/commit/c9d9f78feb1467e73fd29356c040bde1c104f29fWEB
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