7-Zip before 26.06 contains a heap out-of-bounds write vulnerability in the LZX decoder that lets attackers corrupt
Source GCVE Database
Not known to be exploited · CVSS 8.5 High : upgrade to 26.06 soon.
Data as of 10 Nov 2026, 14:32 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 8.5 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 7.8 |
- Patch
- Available – fixed in 26.06
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade 7-Zip to 26.06.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| 7-Zip7-Zip | Affected
| Fixed in
|
GitHub7-Zippkg:github/7-ZipOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fixed version 26.06 or later addresses this vulnerability. Users should upgrade to 7-Zip version 26.06 or newer to remediate this issue. No other mitigations or temporary workarounds are indicated. Since this is not a cloud service, manual patching is required.
Description
7-Zip versions before 26.06 have a heap out-of-bounds write vulnerability in the LZX decoder. This flaw occurs when processing continuation CAB volumes that declare a smaller window, leading to memory corruption. An attacker can craft multi-volume CAB archives that exploit a stale _pos value to bypass bounds checks, potentially allowing arbitrary code execution when a victim extracts these archives.
References
- nvd.nist.gov/vuln/detail/CVE-2026-125742 (opens in a new tab)
- github.com/ip7z/7zip/commit/d3296e39e1f1f92c7b41c0c3848e65640428d42d (opens in a new tab)
- github.com/ip7z/7zip/blob/26.05/CPP/7zip/Compress/LzxDecoder.cpp (opens in a new tab)
- github.com/ip7z/7zip/releases/tag/26.06 (opens in a new tab)
- potion-brew.pages.dev/posts/7zip-cab-lzx-window-desync-rce (opens in a new tab)
- vulncheck.com/advisories/7-zip-before-26.06-heap-out-of-bounds-write-via-lzx-decoder-in-cab-extraction (opens in a new tab)