DEBIAN-CVE-2026-6100

Advisory lineage Upstream: 1 Downstream: 0
Upstream
CVE-2026-6100
Published: 13 Apr 2026, 18:16
Last modified:11 Jul 2026, 21:00

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.1 CRITICAL
4.0 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

13 Apr 2026, 18:16
Published
Vulnerability first disclosed
11 Jul 2026, 21:00
Last Modified
Vulnerability information updated

Description

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 Metrics

  • v4.0•CRITICAL•Score: 9.1CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected Systems

  • debian•pypy3

    all | all | all | all

  • debian•python2.7

    all

  • debian•python3.11

    all | < 3.11.2-6+deb12u8

  • debian•python3.13

    all | all | < 3.13.5-2+deb13u2 | < 3.13.14-1

  • debian•python3.14

    all | < 3.14.5~rc1-1

  • debian•python3.9

    all | < 3.9.2-1+deb11u6

References (1)