CVE-2026-125742

high

Description

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.

References

https://www.vulncheck.com/advisories/7-zip-before-26.06-heap-out-of-bounds-write-via-lzx-decoder-in-cab-extraction

https://potion-brew.pages.dev/posts/7zip-cab-lzx-window-desync-rce/

https://github.com/ip7z/7zip/releases/tag/26.06

https://github.com/ip7z/7zip/commit/d3296e39e1f1f92c7b41c0c3848e65640428d42d

https://github.com/ip7z/7zip/blob/26.05/CPP/7zip/Compress/LzxDecoder.cpp#L1496-L1513

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-120897

Details

Source: Mitre, NVD

Published: 2026-11-10

Updated: 2026-11-10

Risk Information

CVSS v2

Base Score: 7.2

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Severity: High

CVSS v4

Base Score: 8.5

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: High