CVE-2026-100781CWE-119

CVE-2026-100781

Critical · published September 29, 2026

CVSS v3.1
9.6
EPSS
0%
Percentile
24.7
In the wild
Unconfirmed
What it is

Sandbox escape due to incorrect boundary conditions 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
9.6 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00328 · 24.7th percentile
Weakness
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer
Published
2026-09-29T17:17Z
Affected products (7)
ProductVersionsFixed in
mozilla/firefox< 157.0.0157.0.0
mozilla/firefox≥ 115.1.0, < 115.42.0115.42.0
mozilla/firefox≥ 140.0, < 140.17.0140.17.0
mozilla/firefox≥ 153.0, < 153.4.0153.4.0
mozilla/thunderbird< 157.0157.0
mozilla/thunderbird≥ 140.0, < 140.17.0140.17.0
mozilla/thunderbird≥ 153.0, < 153.4.0153.4.0
References (8)
https://bugzilla.mozilla.org/show_bug.cgi?id=2068434 · [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
    Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component
    cvelistv5