CVE-2026-9669

Impact

bz2.BZ2Decompressor objects could be reused after a decompression error. If an application caught the resulting OSError and retried with the same decompressor, crafted input could cause the decompressor to resume from an invalid internal state and perform out-of-bounds writes to a stack buffer. This could crash the process when processing untrusted data.

Affected packages

This record carries no package version data, so it cannot be matched against a dependency list automatically. Read the advisory and compare your version by hand.

Weakness classification

References

• NVD record
• CVE.org record
• https://github.com/python/cpython/commit/157a5df8cb5d82b33f918a7489e72ce95ceb12b6
• https://github.com/python/cpython/commit/1ba6135eae75ad8413413caeeedb56ae72320636
• https://github.com/python/cpython/commit/5755d0f083949ff3c5bf3a37e673e24e306b036e
• https://github.com/python/cpython/commit/619a12b2e545391dc436b3af79dda22337382a6f
• https://github.com/python/cpython/commit/938ec030e90c5e53f1faac6fab1643f14e4f4a79
• https://github.com/python/cpython/commit/991e6cf86496718c4ef00b362d640e00cb5c85b2
• https://github.com/python/cpython/commit/d3ca26983dfbccdf609f24ff5877dc3118e4702d
• https://github.com/python/cpython/issues/150599
• https://github.com/python/cpython/pull/150600
• https://mail.python.org/archives/list/security-announce@python.org/thread/DBJZETMGUIFK7DVUWMOXHD3Z6IX2QPSX/
• http://www.openwall.com/lists/oss-security/2026/06/08/17