Out-of-bounds write in ClamAV - CVE-2026-20337
Published: August 7, 2026
Vulnerability identifier: #VU141296
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-20337
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to write beyond a heap allocation.
The vulnerability exists due to out-of-bounds write in ZIP catalogue capacity tracking when indexing local file headers. A remote attacker can provide a crafted ZIP archive to write beyond a heap allocation.
Affected software
ClamAV
How to mitigate CVE-2026-20337
Install security update from vendor's website.
ClamAV - update to 1.5.4