CVE-2026-6783: Incorrect boundary conditions, integer overflow in the Audio/Video: Playback component

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-21 · updated 2026-10-26
Weakness: CWE-190

Description

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

Affected products

Mozilla Firefox: before 150.0 — fixed in 150.0
Mozilla Thunderbird: before 150.0 — fixed in 150.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 150.0; Mozilla Thunderbird 150.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2027564
https://www.mozilla.org/security/advisories/mfsa2026-30/
https://www.mozilla.org/security/advisories/mfsa2026-33/

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