Vulnerability · Published Feb 25, 2026 · Assigned by GitHub_M

CVE-2026-27711NanaZip UFS Archive Parser Memory Corruption via Unvalidated Directory Record Length

Medium 5.1

In plain English

A medium-severity out-of-bounds read in NanaZip from M2Team. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities).

Severity (CVSS 4.0)5.1Medium

Exploit odds (30 days)0.2%top 93.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

NanaZip is an open source file archive. Starting in version 5.0.1252.0 and prior to versions 6.0.1638.0 and 6.5.1638.0, a memory corruption vulnerability in NanaZip’s UFS parser allows a crafted `.ufs/.ufs2/.img` file to trigger out-of-bounds memory access during archive open/listing. The bug is reachable via normal user file-open flow and can cause process crash, hang, and potentially exploitable heap corruption. Versions 6.0.1638.0 and 6.5.1638.0 fix the issue.

Affected products (as reported)

Vendor	Product	Versions
M2Team	NanaZip	>= 5.0.1252.0, < 6.0.1638.0>= 6.1, < 6.5.1638.0

Weakness: CWE-125 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

https://github.com/M2Team/NanaZip/security/advisories/GHSA-rjwv-4w7x-hc9c x_refsource_CONFIRM