CVE-2026-9669
bz2.BZ2Decompressor reuse after error can cause a stack buffer overflow
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-121 |
| Vendor | python software foundation |
| Product | cpython |
| Published | Jun 8, 2026 |
| Last Updated | Jun 8, 2026 |
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Affected Versions
Python Software Foundation / CPython
0 < 3.16.0
References
github.com: https://github.com/python/cpython/pull/150600 mail.python.org: https://mail.python.org/archives/list/[email protected]/thread/DBJZETMGUIFK7DVUWMOXHD3Z6IX2QPSX/ github.com: https://github.com/python/cpython/issues/150599 openwall.com: http://www.openwall.com/lists/oss-security/2026/06/08/17
Credits
🔍 Bitshift (https://github.com/TheShiftedBit) Emma Smith (https://github.com/emmatyping) Stan Ulbrych (https://github.com/StanFromIreland) Serhiy Storchaka (https://github.com/serhiy-storchaka)