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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-42446

From 5.0.1252.0 to before 6.0.1698.0, a stack-based out-of-bounds read exists in the ZealFS filesystem image parser in NanaZip.

HIGH 7.1EPSS 0.12%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

NanaZip is an open source file archive. From 5.0.1252.0 to before 6.0.1698.0, a stack-based out-of-bounds read exists in the ZealFS filesystem image parser in NanaZip. The vulnerability is triggered when opening a crafted ZealFS v1 filesystem image. An attacker-controlled BitmapSize field in the file header drives an unbounded loop that reads past the end of a stack-allocated ZEALFS_V1_HEADER structure. This vulnerability is fixed in 6.0.1698.0.

CVSS 3.1
7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
EPSS
0.12% probability · 2th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-125
Affected
m2team/nanazip
Source
security-advisories@github.com
EPSS trend
0%3%5%27 October 2026: 0.12%27 October 202627 October 2026

EPSS 0.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.