What’s Vulnerable › Vulnerabilities

CVE-2020-36430

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-07-20 · updated 2026-06-17
• Weakness: CWE-787

Description

libass 0.15.x before 0.15.1 has a heap-based buffer overflow in decode_chars (called from decode_font and process_text) because the wrong integer data type is used for subtraction.

Affected products

• Fedoraproject Fedora: 34
• Libass Project Libass: from 0.15.0 before 0.15.1 — fixed in 0.15.1

How to fix

Upgrade to a fixed version: Libass Project Libass 0.15.1. Check the vendor advisory for mitigations.

References

• https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26674
• https://github.com/google/oss-fuzz-vulns/blob/main/vulns/libass/OSV-2020-2099.yaml
• https://github.com/libass/libass/commit/017137471d0043e0321e377ed8da48e45a3ec632
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6JUXFQUJ32GWG5E46A63DFDCYJAF3VU6/
• https://security.gentoo.org/glsa/202208-13
• https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26674
• https://github.com/google/oss-fuzz-vulns/blob/main/vulns/libass/OSV-2020-2099.yaml
• https://github.com/libass/libass/commit/017137471d0043e0321e377ed8da48e45a3ec632
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6JUXFQUJ32GWG5E46A63DFDCYJAF3VU6/
• https://security.gentoo.org/glsa/202208-13

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