CVE-2026-20031
Publication date 4 March 2026
Last updated 27 April 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| clamav | 26.04 LTS resolute |
Fixed 1.4.4+dfsg-0ubuntu0.26.04.1
|
| 25.10 questing |
Fixed 1.4.4+dfsg-0ubuntu0.25.10.1
|
|
| 24.04 LTS noble |
Fixed 1.4.4+dfsg-0ubuntu0.24.04.1
|
|
| 22.04 LTS jammy |
Fixed 1.4.4+dfsg-0ubuntu0.22.04.1
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
Notes
leosilva
Building ClamAV requires rust compiler >= 1.61 releases as bionic, xenial and trusty are not covered by that version of rustc. ClamAV new versions can't build in these releases anymore.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.3 · Medium
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | Low |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |