CVE-2026-20031

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.

These are all security issues fixed in the clamav-1.5.2-1.1 package on the GA media of openSUSE Tumbleweed.

This update for clamav fixes the following issues:

Update to clamav 1.5.2:

Security issue:

• CVE-2026-20031: improper error handling in the HTML CSS module when splitting UTF-8 strings can lead to denial of service conditions via a crafted HTML file (bsc#1259207).

Non security issue:

• Support transactional updates (jsc#PED-14819).

Changelog:

• Fixed a possible infinite loop when scanning some JPEG files by upgrading affected ClamAV dependency, a Rust image library.
• The CVD verification process will now ignore certificate files in the CVD certs directory when the user lacks read permissions.
• Freshclam: Fix CLD verification bug with PrivateMirror option.
• Upgraded the Rust bytes dependency to a newer version to resolve RUSTSEC-2026-0007 advisory.
• Fixed a possible crash caused by invalid pointer alignment on some platforms.

This update for clamav fixes the following issues:

Update to clamav 1.5.2:

Security issue:

• CVE-2026-20031: improper error handling in the HTML CSS module when splitting UTF-8 strings can lead to denial of service conditions via a crafted HTML file (bsc#1259207).

Non security issue:

• Support transactional updates (jsc#PED-14819).

Changelog:

• Fixed a possible infinite loop when scanning some JPEG files by upgrading affected ClamAV dependency, a Rust image library.
• The CVD verification process will now ignore certificate files in the CVD certs directory when the user lacks read permissions.
• Freshclam: Fix CLD verification bug with PrivateMirror option.
• Upgraded the Rust bytes dependency to a newer version to resolve RUSTSEC-2026-0007 advisory.
• Fixed a possible crash caused by invalid pointer alignment on some platforms.
• Minimal required Rust version is now 1.87.

This update for clamav fixes the following issues:

Update to clamav 1.5.2:

Security issue:

• CVE-2026-20031: improper error handling in the HTML CSS module when splitting UTF-8 strings can lead to denial of service conditions via a crafted HTML file (bsc#1259207).

Non security issue:

• Support transactional updates (jsc#PED-14819).

Changelog:

• Fixed a possible infinite loop when scanning some JPEG files by upgrading affected ClamAV dependency, a Rust image library.
• The CVD verification process will now ignore certificate files in the CVD certs directory when the user lacks read permissions.
• Freshclam: Fix CLD verification bug with PrivateMirror option.
• Upgraded the Rust bytes dependency to a newer version to resolve RUSTSEC-2026-0007 advisory.
• Fixed a possible crash caused by invalid pointer alignment on some platforms.
• Minimal required Rust version is now 1.87.

This update for clamav fixes the following issues:

Update to clamav 1.5.2:

• CVE-2026-20031: improper error handling in the HTML CSS module when splitting UTF-8 strings can lead to denial of service conditions via a crafted HTML file (bsc#1259207).

Non security issue:

• Support transactional updates (jsc#PED-14819).
• Require main and library packages to be of the same version and release (bsc#1258072).

Changelog:

• Fixed a possible infinite loop when scanning some JPEG files by upgrading affected ClamAV dependency, a Rust image library.
• The CVD verification process will now ignore certificate files in the CVD certs directory when the user lacks read permissions.
• Freshclam: Fix CLD verification bug with PrivateMirror option.
• Upgraded the Rust bytes dependency to a newer version to resolve RUSTSEC-2026-0007 advisory.
• Fixed a possible crash caused by invalid pointer alignment on some platforms.
• Minimal required Rust version is now 1.87.

This update for clamav fixes the following issues:

Update to clamav 1.5.2:

Security issue:

• CVE-2026-20031: improper error handling in the HTML CSS module when splitting UTF-8 strings can lead to denial of service conditions via a crafted HTML file (bsc#1259207).

Non security issue:

• Support transactional updates (jsc#PED-14819).

Changelog:

• Fixed a possible infinite loop when scanning some JPEG files by upgrading affected ClamAV dependency, a Rust image library.
• The CVD verification process will now ignore certificate files in the CVD certs directory when the user lacks read permissions.
• Freshclam: Fix CLD verification bug with PrivateMirror option.
• Upgraded the Rust bytes dependency to a newer version to resolve RUSTSEC-2026-0007 advisory.
• Fixed a possible crash caused by invalid pointer alignment on some platforms.
• Minimal required Rust version is now 1.87.

This update for clamav fixes the following issues:

Update to clamav 1.5.2:

Security issue:

• CVE-2026-20031: improper error handling in the HTML CSS module when splitting UTF-8 strings can lead to denial of service conditions via a crafted HTML file (bsc#1259207).

Non security issue:

• Support transactional updates (jsc#PED-14819).

Changelog:

• Fixed a possible infinite loop when scanning some JPEG files by upgrading affected ClamAV dependency, a Rust image library.
• The CVD verification process will now ignore certificate files in the CVD certs directory when the user lacks read permissions.
• Freshclam: Fix CLD verification bug with PrivateMirror option.
• Upgraded the Rust bytes dependency to a newer version to resolve RUSTSEC-2026-0007 advisory.
• Fixed a possible crash caused by invalid pointer alignment on some platforms.

It was discovered that ClamAV incorrectly handled certain HTML files. A remote attacker could possibly use this issue to cause ClamAV to crash, resulting in a denial of service.