CVE-2026-125742

EUVD-2026-120897
7-Zip before 26.06 contains a heap out-of-bounds write vulnerability in the LZX decoder that lets attackers corrupt memory when a continuation CAB volume declares a smaller window. Attackers can entice victims to extract crafted multi-volume CAB archives, where a stale _pos value bypasses bounds checks, enabling arbitrary code execution.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.8 HIGH
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Debian logo
Debian Releases
Debian Product
Codename
7zip
bookworm
vulnerable
bookworm (security)
vulnerable
forky
vulnerable
sid
26.06+dfsg-1
fixed
trixie
no-dsa
p7zip
bookworm
vulnerable
bookworm (security)
vulnerable
trixie
16.02+transitional.1
fixed
Common Weakness Enumeration
References
https://github.com/ip7z/7zip/blob/26.05/CPP/7zip/Compress/LzxDecoder.cpp#L1496-L1513
https://github.com/ip7z/7zip/commit/d3296e39e1f1f92c7b41c0c3848e65640428d42d
https://github.com/ip7z/7zip/releases/tag/26.06
https://potion-brew.pages.dev/posts/7zip-cab-lzx-window-desync-rce/
https://www.vulncheck.com/advisories/7-zip-before-26.06-heap-out-of-bounds-write-via-lzx-decoder-in-cab-extraction