Improper error handling in ClamAV - CVE-2026-20031

Vulnerability identifier: #VU123663

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-20031

CWE-ID: CWE-388

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service attack.

The vulnerability exists due to incorrect error handling when parsing HTML code. A remote attacker can pass specially crafted input to the application and perform a denial of service attack. 

ClamAV
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
Basesystem Module
openSUSE Leap
clamav-docs-html
clamav-milter-debuginfo
clamav-devel
libclammspack0-debuginfo
libclamav12
libfreshclam4-debuginfo
libclamav12-debuginfo
libfreshclam4
clamav-debugsource
clamav
libclammspack0
clamav-debuginfo
clamav-milter

Install updates from vendor's website.

ClamAV - addressed in versions 1.4.4, 1.5.2
clamav-docs-html - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
clamav-milter-debuginfo - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
clamav-devel - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
libclammspack0-debuginfo - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
libclamav12 - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
libfreshclam4-debuginfo - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
libclamav12-debuginfo - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
libfreshclam4 - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
clamav-debugsource - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
clamav - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
libclammspack0 - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
clamav-debuginfo - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1
clamav-milter - addressed in versions 1.5.2-3.53.1, 1.5.2-150400.13.5.1, 1.5.2-150600.18.25.1

• https://blog.clamav.net/2026/03/clamav-152-and-144-security-patch.html

• Denial of service in ClamAV
• SUSE update for clamav
• SUSE update for clamav
• SUSE update for clamav
• SUSE update for clamav