USN-8815-1: libass vulnerabilities
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)
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/libass9to a version that resolves this vulnerability.Fixed in Ubuntu Pro - Upgrade
Upgrade
ubuntu/libass4to a version that resolves this vulnerability.Fixed in Ubuntu Pro - Upgrade
Upgrade
ubuntu/libassto a version that resolves this vulnerability.Fixed in 0.10.1-3ubuntu1+esm2 - Upgrade
Upgrade
ubuntu/libassto a version that resolves this vulnerability.Fixed in 1:0.14.0-1ubuntu0.1~esm1 - Upgrade
Upgrade
ubuntu/libassto a version that resolves this vulnerability.Fixed in 1:0.14.0-2ubuntu0.1~esm1 - Upgrade
Upgrade
ubuntu/libassto a version that resolves this vulnerability.Fixed in 1:0.17.1-2ubuntu0.1~esm1 - Upgrade
Upgrade
ubuntu/libassto a version that resolves this vulnerability.Fixed in 1:0.17.4-2ubuntu0.1~esm1
Event History
Child vulnerabilities
Contains the following vulnerabilities.
Frequently Asked Questions
Which vulnerability identifiers are covered by this advisory?
The advisory references CVE-2026-61627, CVE-2026-61626, and CVE-2020-26682.