CVE-2026-100797CWE-416

CVE-2026-100797

High · published September 29, 2026

CVSS v3.1
8.8
EPSS
0%
Percentile
15.6
In the wild
Unconfirmed
What it is

Privilege escalation due to use-after-free in the Graphics: WebRender component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00251 · 15.6th percentile
Weakness
CWE-416 · Use After Free
Published
2026-09-29T17:17Z
Affected products (7)
ProductVersionsFixed in
mozilla/firefox< 115.42.0115.42.0
mozilla/firefox≥ 116.0, < 140.17.0140.17.0
mozilla/firefox≥ 141.0, < 153.4.0153.4.0
mozilla/firefox≥ 154.0.0, < 157.0.0157.0.0
mozilla/thunderbird< 140.17.0140.17.0
mozilla/thunderbird≥ 141.0, < 153.4.0153.4.0
mozilla/thunderbird≥ 154.0, < 157.0157.0
References (8)
https://bugzilla.mozilla.org/show_bug.cgi?id=2050542 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-100/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-101/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-102/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-103/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-97/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-98/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-99/ · [email protected]
EPSS history
Timeline
  • 01 OCT 03:44Z
    EPSS moved — → 0%
    epss
  • 29 SEP 12:36Z
    Privilege escalation due to use-after-free in the Graphics: WebRender component
    cvelistv5