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Fencer Vulns
high 7.5

CVE-2026-20338 json

ClamAV ZIP File Format Processing Memory Corruption Vulnerability

published 2026-08-07 3 mo ago modified 2026-10-23 16 d ago also EUVD-2026-54529

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

Summary

A vulnerability in the zip archive parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device.

This vulnerability is due to improper memory handling when processing content in zip files during scanning. An attacker could exploit this vulnerability by submitting a crafted zip file for scanning. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate as a result of a memory double-free, resulting in a DoS condition on the affected software.

Patch / fix

  • cisco clam_antivirus 1.5.4-0
  • cisco clamav 1.5.4-0
  • clamav clamav 1.5.4-0
  • clamavs clamav 1.5.4-0
  • clam_anti-virus clamav 1.5.4-0
  • clamav Ubuntu 22.04 LTS 1.5.4+dfsg-0ubuntu0.22.04.1
  • clamav Ubuntu 24.04 LTS 1.5.4+dfsg-0ubuntu0.24.04.1
  • clamav Ubuntu 26.04 LTS 1.5.4+dfsg-0ubuntu0.26.04.1

ubuntu advisories UBUNTU-CVE-2026-20338

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • clamav SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +6 more 1.5.4-150400.13.11.1
  • clamav SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Basesystem 15 SP7 1.5.4-150600.18.31.1
  • clamav SLES 16.0, SLES for SAP applications 16.0 1.5.4-160000.1.1
  • clamav SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 1.5.4-3.59.1

suse advisories SUSE-SU-2026:4208-1SUSE-SU-2026:4180-1SUSE-SU-2026:4179-1SUSE-SU-2026:23706-1SUSE-SU-2026:23727-1

  • clamav openSUSE Leap 16.0 1.5.4-160000.1.1
  • clamav openSUSE Tumbleweed 1.5.4-1.1

opensuse advisories openSUSE-SU-2026:21831-1openSUSE-SU-2026:11583-1

  • clamav Azure Linux 3.0 1.5.4-1

azure linux advisories AZL-95459

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Cisco Cisco Secure Endpoint

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.