CVE-2026-4688

Description

Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS Metrics

• v3.1•CRITICAL•Score: 10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
• v3.1•CRITICAL•Score: 9.6CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.03%• Percentile: 8%

Techniques & Countermeasures

• CWE-416•Use After Free

  The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

• mozilla•firefox

  ≥ unspecified, < 149 | < 140.9.0 | < 149.0

• mozilla•firefox_esr

  ≥ unspecified, < 140.9

• mozilla•thunderbird

  ≥ unspecified, < 149 | ≥ unspecified, < 140.9

References (5)

• https://bugzilla.mozilla.org/show_bug.cgi?id=2016373
• https://www.mozilla.org/security/advisories/mfsa2026-20/
• https://www.mozilla.org/security/advisories/mfsa2026-22/
• https://www.mozilla.org/security/advisories/mfsa2026-23/
• https://www.mozilla.org/security/advisories/mfsa2026-24/