CVE-2026-84121

Public on 2026-09-01
Modified on 2026-09-01
Description
Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2.
Severity
Important severity
Important
See what this means
CVSS v3 Base Score
8.3
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Firefox Extra firefox Pending Fix
Amazon Linux 2023 firefox Pending Fix
Amazon Linux 2027 Preview firefox Pending Fix
Amazon Linux 2 - Firefox Extra firefox-amzn-policies-generic Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 8.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

References

FAQs regarding Amazon Linux ALAS/CVE Severity Red Hat: CVE-2026-84121 Mitre: CVE-2026-84121