CVE-2026-8947

Published: May 19, 2026Modified: Jul 15, 2026

7.5

Vector

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

Exploitability: 1.6 / Impact: 5.9

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary)

Description

Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Affected (4)

Products: Mozilla: Firefox, Thunderbird

Mozilla

2 products

Firefox

Thunderbird

Configuration A

4 vulnerable

Vulnerable Software	Affected Versions
Mozilla Firefox	Before 151.0.0
Mozilla Firefox	Before 115.36.0
Mozilla Firefox	From 140.0 to 140.11.0
Mozilla Thunderbird	Before 140.11

Related CWEs

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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

CWE-825

Expired Pointer Dereference

The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.

References (30)

https://bugzilla.mozilla.org/show_bug.cgi?id=2038439

Source: security@mozilla.org

Permissions Required

https://www.mozilla.org/security/advisories/mfsa2026-46/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-47/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-48/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-50/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-51/

Source: security@mozilla.org

Vendor Advisory

https://access.redhat.com/errata/RHSA-2026:21378