CVE-2026-100779

high

Description

Use-after-free in the XSLT component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

References

https://www.mozilla.org/security/advisories/mfsa2026-99/

https://www.mozilla.org/security/advisories/mfsa2026-98/

https://www.mozilla.org/security/advisories/mfsa2026-97/

https://www.mozilla.org/security/advisories/mfsa2026-103/

https://www.mozilla.org/security/advisories/mfsa2026-102/

https://www.mozilla.org/security/advisories/mfsa2026-101/

https://www.mozilla.org/security/advisories/mfsa2026-100/

https://bugzilla.mozilla.org/show_bug.cgi?id=2068417

Details

Source: Mitre, NVD

Published: 2026-09-29

Updated: 2026-09-30

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 8.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00311