SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-8091

This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.

CRITICAL 9.8EPSS 0.47%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.47% probability · 39th percentile
CISA KEV
Not listed
Weakness
CWE-754, CWE-805
Affected
mozilla/firefox · mozilla/thunderbird
Source
security@mozilla.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.