CVE-2026-4689

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-4689
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.

10.0 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References
Link Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=2016374 Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-20/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-21/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-22/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-23/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-24/ Vendor Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
History

13 Apr 2026, 15:17

Type Values Removed Values Added
Summary (en) Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9. (en) 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.

25 Mar 2026, 15:34

Type Values Removed Values Added
CWE CWE-754
CPE cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
First Time Mozilla
Mozilla firefox
Mozilla thunderbird
References () https://bugzilla.mozilla.org/show_bug.cgi?id=2016374 - () https://bugzilla.mozilla.org/show_bug.cgi?id=2016374 - Permissions Required
References () https://www.mozilla.org/security/advisories/mfsa2026-20/ - () https://www.mozilla.org/security/advisories/mfsa2026-20/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-21/ - () https://www.mozilla.org/security/advisories/mfsa2026-21/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-22/ - () https://www.mozilla.org/security/advisories/mfsa2026-22/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-23/ - () https://www.mozilla.org/security/advisories/mfsa2026-23/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-24/ - () https://www.mozilla.org/security/advisories/mfsa2026-24/ - Vendor Advisory

25 Mar 2026, 15:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : 9.3 		v2 : unknown
v3 : 10.0

25 Mar 2026, 14:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 9.3
Summary
  • (es) Escape de sandbox debido a condiciones de límite incorrectas, desbordamiento de entero en el componente XPCOM. Esta vulnerabilidad afecta a Firefox &lt; 149, Firefox ESR &lt; 115.34, Firefox ESR &lt; 140.9, Thunderbird &lt; 149 y Thunderbird &lt; 140.9.
CWE CWE-190
CWE-120

24 Mar 2026, 21:16

Type Values Removed Values Added
Summary (en) Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (en) Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
References
  • () https://www.mozilla.org/security/advisories/mfsa2026-23/ -
  • () https://www.mozilla.org/security/advisories/mfsa2026-24/ -

24 Mar 2026, 13:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-03-24 13:16

Updated : 2026-04-13 15:17

NVD link : CVE-2026-4689

Mitre link : CVE-2026-4689

CVE.ORG link : CVE-2026-4689

JSON object : View

Products Affected

mozilla

  • firefox
  • thunderbird
CWE
CWE-190

Integer Overflow or Wraparound

CWE-754

Improper Check for Unusual or Exceptional Conditions

CWE-120

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')