CVE-2026-20031 | ClamAV CSS Image Parsing Error Handling Denial of Service Vulnerability

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.

Published: 2026-03-04 Last update: 2026-03-05 Assigner: [email protected] Source: [email protected]
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-20031 is rated Low Risk (25.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.04%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-20031

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-21 0.09% 0.04% -0.05%
2 2026-03-05 — 0.09% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20031

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-20031

OS Trackers for CVE-2026-20031

vendor priority summary link
alpine — CVE-2026-20031: 1 source package rows (clamav); 2 state rows across 2 repos (3.23-community, edge-community); fixed 2, open 0. https://security.alpinelinux.org/vuln/CVE-2026-20031
debian not yet assigned CVE-2026-20031 not yet assigned priority: Debian including 1 source packages (clamav), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-20031
suse medium CVE-2026-20031 severity moderate: SUSE including 45 source package names (clamav, clamav-1.4.4-36.19.1, …), 206 product×package rows across 27 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (27 product lines)): First Fixed 84, Fixed 56, Will Not Fix 56, Known Not Affected 10. https://www.suse.com/security/cve/CVE-2026-20031/
ubuntu medium CVE-2026-20031 medium priority: Ubuntu including 1 source packages (clamav), 9 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): needs-triage 5, released 4. https://ubuntu.com/security/CVE-2026-20031

Affected software / configurations for CVE-2026-20031

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-20031

cvelogic Threat Intelligence