Skip to content
CVE PROGRAM SOURCE RECORD9.6 Critical

CVE-2026-84121

Sandbox escape due to use-after-free in the DOM: Security component

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, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Mozilla Firefox

  • 115.40 to ≤ 115.*unaffected
  • 140.15 to ≤ 140.*unaffected
  • 153.2 to ≤ 153.*unaffected
  • 155 to ≤ *unaffected

Mozilla Thunderbird

  • 140.15 to ≤ 140.*unaffected
  • 153.2 to ≤ 153.*unaffected
  • 155 to ≤ *unaffected

References