CVE-2026-2776

Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVSS v3 10.0 CRITICAL

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=2015266	Issue Tracking Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-13/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-14/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-15/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-16/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-17/	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		(es) Escape de sandbox debido a condiciones de contorno incorrectas en el componente de Telemetría en el Software Externo. Esta vulnerabilidad afecta a Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, y Thunderbird < 140.8.
Summary	(en) Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.	(en) Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

28 Feb 2026, 04:16

Type	Values Removed	Values Added
CWE		CWE-119

25 Feb 2026, 16:25

Type	Values Removed	Values Added
CWE		NVD-CWE-noinfo
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:::*
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 10.0
First Time		Mozilla Mozilla firefox Mozilla thunderbird
References	~~() https://bugzilla.mozilla.org/show_bug.cgi?id=2015266 -~~	() https://bugzilla.mozilla.org/show_bug.cgi?id=2015266 - Issue Tracking, Permissions Required
References	~~() https://www.mozilla.org/security/advisories/mfsa2026-13/ -~~	() https://www.mozilla.org/security/advisories/mfsa2026-13/ - Vendor Advisory
References	~~() https://www.mozilla.org/security/advisories/mfsa2026-14/ -~~	() https://www.mozilla.org/security/advisories/mfsa2026-14/ - Vendor Advisory
References	~~() https://www.mozilla.org/security/advisories/mfsa2026-15/ -~~	() https://www.mozilla.org/security/advisories/mfsa2026-15/ - Vendor Advisory
References	~~() https://www.mozilla.org/security/advisories/mfsa2026-16/ -~~	() https://www.mozilla.org/security/advisories/mfsa2026-16/ - Vendor Advisory
References	~~() https://www.mozilla.org/security/advisories/mfsa2026-17/ -~~	() https://www.mozilla.org/security/advisories/mfsa2026-17/ - Vendor Advisory

24 Feb 2026, 18:29

Type	Values Removed	Values Added
References		() https://www.mozilla.org/security/advisories/mfsa2026-16/ - () https://www.mozilla.org/security/advisories/mfsa2026-17/ -
Summary	~~(en) Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8.~~	(en) Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

24 Feb 2026, 14:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-02-24 14:16

Updated : 2026-04-13 15:17

NVD link : CVE-2026-2776

Mitre link : CVE-2026-2776

CVE.ORG link : CVE-2026-2776

JSON object : View

Products Affected

mozilla

firefox
thunderbird

CWE

NVD-CWE-noinfo CWE-119

Improper Restriction of Operations within the Bounds of a Memory Buffer

10.0 /10