Use-after-free in lzma.LZMADecompressor, bz2.BZ2Decompressor, and gzip.GzipFile after re-use under memory pressure
28Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 9.1epss 0.6%
probabilidad de explotación
0.6%top 56% de las CVE
explotación observada
noninguna fuente lo reporta
Use-after-free (UAF) was possible in the `lzma.LZMADecompressor`, `bz2.BZ2Decompressor`, and `gzip.GzipFile` when a memory allocation fails with a `MemoryError` and the decompression instance is re-used. This scenario can be triggered if the process is under memory pressure. The fix cleans up the dangling pointer in this specific error condition.
The vulnerability is only present if the program re-uses decompressor instances across multiple decompression calls even after a `MemoryError` is raised during decompression. Using the helper functions to one-shot decompress data such as `lzma.decompress()`, `bz2.decompress()`, `gzip.decompress()`, and `zlib.decompress()` are not affected as a new decompressor instance is used per call. If the decompressor instance is not re-used after an error condition, this usage is similarly not vulnerable.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Productos afectados
Python Software Foundation · CPythonReferencias
https://access.redhat.com/errata/RHSA-2026:10117https://access.redhat.com/errata/RHSA-2026:10140https://access.redhat.com/errata/RHSA-2026:10141https://access.redhat.com/errata/RHSA-2026:10711https://access.redhat.com/errata/RHSA-2026:10745https://access.redhat.com/errata/RHSA-2026:10774https://access.redhat.com/errata/RHSA-2026:10949https://access.redhat.com/errata/RHSA-2026:10950https://access.redhat.com/errata/RHSA-2026:11062https://access.redhat.com/errata/RHSA-2026:11077https://access.redhat.com/errata/RHSA-2026:11768https://access.redhat.com/errata/RHSA-2026:13692