CVE-2026-4689

Severity CVSS v4.0:

Pending analysis

Type:

CWE-190 Integer Overflow or Wraparound

Publication date:

24/03/2026

Last modified:

13/04/2026

Description

Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 10.00 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

10.00

Severity 3.x

CRITICAL

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:mozilla:firefox:::::esr:::*		115.34.0 (excluding)
cpe:2.3:a:mozilla:firefox:::::-:::*		149.0 (excluding)
cpe:2.3:a:mozilla:firefox:::::esr:::*	128.0 (including)	140.9.0 (excluding)
cpe:2.3:a:mozilla:thunderbird:::::esr:::*		140.9.0 (excluding)
cpe:2.3:a:mozilla:thunderbird:::::-:::*		149.0 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-4689

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools