SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-4684

Race condition, use-after-free in the Graphics: WebRender component.

HIGH 7.5EPSS 0.35%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.35%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Race condition, use-after-free in the Graphics: WebRender component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
0.35% probability · 29th percentile
CISA KEV
Not listed
Weakness
CWE-362, CWE-416, CWE-364
Affected
mozilla/firefox
Source
security@mozilla.org

References

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