CVE-2026-2777

Privilege escalation in the Messaging System component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=2015305	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

No history.

Information

Published : 2026-02-24 14:16

Updated : 2026-02-25 19:43

NVD link : CVE-2026-2777

Mitre link : CVE-2026-2777

CVE.ORG link : CVE-2026-2777

JSON object : View

Products Affected

mozilla

firefox
thunderbird

CWE

NVD-CWE-noinfo CWE-269

Improper Privilege Management

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