bz2.BZ2Decompressor reuse after error can cause a stack buffer overflow
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.2epss 0.4%
exploitation probability
0.4%top 65% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
Python Software Foundation · CPythonReferences
https://github.com/python/cpython/commit/157a5df8cb5d82b33f918a7489e72ce95ceb12b6https://github.com/python/cpython/commit/1ba6135eae75ad8413413caeeedb56ae72320636https://github.com/python/cpython/commit/5755d0f083949ff3c5bf3a37e673e24e306b036ehttps://github.com/python/cpython/commit/619a12b2e545391dc436b3af79dda22337382a6fhttps://github.com/python/cpython/commit/938ec030e90c5e53f1faac6fab1643f14e4f4a79https://github.com/python/cpython/commit/991e6cf86496718c4ef00b362d640e00cb5c85b2https://github.com/python/cpython/commit/d3ca26983dfbccdf609f24ff5877dc3118e4702dhttps://github.com/python/cpython/issues/150599https://github.com/python/cpython/pull/150600https://mail.python.org/archives/list/security-announce@python.org/thread/DBJZETMGUIFK7DVUWMOXHD3Z6IX2QPSX/http://www.openwall.com/lists/oss-security/2026/06/08/17