Vulnerability · Published May 12, 2026 · Assigned by GitHub_M

CVE-2026-44215NanaZip: Heap out-of-bounds write in NanaZip UFS directory parser

Medium 4.4

In plain English

A medium-severity out-of-bounds write in NanaZip from M2Team. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).

Severity (CVSS 3.1)4.4Medium

Exploit odds (30 days)0.3%top 79.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

NanaZip is an open source file archive. From 5.0.1252.0 to before 6.0.1698.0, a one-byte heap out-of-bounds null write exists in the UFS/UFS2 filesystem image parser in NanaZip. The vulnerability is triggered when opening a crafted UFS filesystem image. The attacker controls the byte offset of the write within a ~254-byte window past the heap allocation boundary. This vulnerability is fixed in 6.0.1698.0.

Affected products (as reported)

Vendor	Product	Versions
M2Team	NanaZip	>= 5.0.1250.0, < 6.0.1698.0

Weakness: CWE-787 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L

References

https://github.com/M2Team/NanaZip/security/advisories/GHSA-44wh-7gc3-w936 x_refsource_CONFIRM