CVE-2026-100794

Published: Sep 29, 2026Modified: Oct 19, 2026

9.6

Vector

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

Exploitability: 2.8 / Impact: 6.0

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

Description

Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.

Affected (6)

Products: Mozilla: Firefox, Thunderbird

2 products

Configuration A

6 vulnerable

Vulnerable Software	Affected Versions
Mozilla Firefox	version < 140.17.0
Mozilla Firefox	141.0 ≤ version < 153.4.0
Mozilla Firefox	154.0.0 ≤ version < 157.0.0
Mozilla Thunderbird	version < 140.17.0
Mozilla Thunderbird	141.0 ≤ version < 153.4.0
Mozilla Thunderbird	154.0 ≤ version < 157.0

Related CWEs

Improper Restriction of Operations within the Bounds of a Memory Buffer

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

References (7)

https://bugzilla.mozilla.org/show_bug.cgi?id=2028871

Source: security@mozilla.org

Permissions Required

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

Source: security@mozilla.org

Vendor Advisory

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

Source: security@mozilla.org

Vendor Advisory

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

Source: security@mozilla.org

Vendor Advisory

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

Source: security@mozilla.org

Vendor Advisory

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

Source: security@mozilla.org

Vendor Advisory

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

Source: security@mozilla.org

Vendor Advisory

Timeline

No history available yet.