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Ubuntu Security NoticesUSN-8815-1

USN-8815-1: libass vulnerabilities

Severity not listed 4 CVEs Published Sep 24, 2026 at 2:57 PM UTC

Summary

It was discovered that libass incorrectly handled parsing operations for specific nested character strings. An attacker could use this issue to cause libass to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2020-24994)

It was discovered that libass incorrectly handled certain outline processing operations. An attacker could use this issue to cause libass to crash, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2020-26682)

It was discovered that libass incorrectly handled certain ASS subtitle files when measuring wrapped lines. An attacker could use this issue to cause libass to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-61627)

It was discovered that libass incorrectly handled certain Matroska subtitle chunks with negative ReadOrder values. An attacker could use this issue to cause libass to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-61626)

Products covered

A separate affected-products list was not included in the collected bulletin.

Remediation

Separate remediation guidance was not included in the collected bulletin.

CVEs in this advisory 4

Updates

  1. Published by Ubuntu

    The publication date reported by the vendor.

  2. Added to SecurityAlert

    We collected the advisory from the official source.

  3. Confirmed at the source

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