What’s Vulnerable › Vulnerabilities

CVE-2026-8091: Incorrect boundary conditions in the Audio/Video: Playback component

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-07 · updated 2026-10-26
• Weakness: CWE-754

Description

Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.

Affected products

• Mozilla Firefox: before 115.35.2; from 140.0 before 140.10.1 — fixed in 115.35.2, 140.10.1
• Mozilla Thunderbird: from 140.0 before 140.10.1 — fixed in 140.10.1

How to fix

Upgrade to a fixed version: Mozilla Firefox 115.35.2, 140.10.1; Mozilla Thunderbird 140.10.1. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2029301
• https://www.mozilla.org/security/advisories/mfsa2026-30/
• https://www.mozilla.org/security/advisories/mfsa2026-33/
• https://www.mozilla.org/security/advisories/mfsa2026-36/
• https://www.mozilla.org/security/advisories/mfsa2026-39/
• https://www.mozilla.org/security/advisories/mfsa2026-42/
• https://access.redhat.com/errata/RHSA-2026:19153
• https://access.redhat.com/errata/RHSA-2026:19157
• https://access.redhat.com/errata/RHSA-2026:19348
• https://access.redhat.com/errata/RHSA-2026:19370
• https://access.redhat.com/errata/RHSA-2026:19588
• https://access.redhat.com/errata/RHSA-2026:20586

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