Vulnerability · Published Mar 4, 2026 · Assigned by cisco
CVE-2026-20031ClamAV CSS Image Parsing Error Handling Denial of Service Vulnerability
Medium 5.3
In plain English
A medium-severity security flaw in Cisco Secure Endpoint from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A vulnerability in the HTML Cascading Style Sheets (CSS) module of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling when splitting UTF-8 strings. An attacker could exploit this vulnerability by submitting a crafted HTML file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the scanning process.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | clamav | 1.4.4-r0 | ALPINE-CVE-2026-20031 |
| Alpine:v3.24 | clamav | 1.4.4-r0 | ALPINE-CVE-2026-20031 |
| Debian:12 | clamav | 1.4.6+dfsg-0+deb12u1 | DEBIAN-CVE-2026-20031 |
| Debian:13 | clamav | no fix listed | DEBIAN-CVE-2026-20031 |
| Debian:14 | clamav | 1.4.4+dfsg-1 | DEBIAN-CVE-2026-20031 |
| Ubuntu:22.04:LTS | clamav | 1.4.4+dfsg-0ubuntu0.22.04.1 | UBUNTU-CVE-2026-20031 |
| Ubuntu:24.04:LTS | clamav | 1.4.4+dfsg-0ubuntu0.24.04.1 | UBUNTU-CVE-2026-20031 |
| Ubuntu:25.10 | clamav | 1.4.4+dfsg-0ubuntu0.25.10.1 | UBUNTU-CVE-2026-20031 |
| Ubuntu:26.04:LTS | clamav | 1.4.4+dfsg-0ubuntu0.26.04.1 | UBUNTU-CVE-2026-20031 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Secure Endpoint | 7.0.56.2.197.3.37.2.136.1.56.3.16.2.57.3.5 |
Weakness: CWE-248 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L