CVE-2026-2777
Received Received - Intake
Privilege Escalation in Firefox Messaging System Before

Publication date: 2026-02-24

Last updated on: 2026-04-13

Assigner: Mozilla Corporation

Description
Privilege escalation in the Messaging System component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
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Meta Information
Published
2026-02-24
Last Modified
2026-04-13
Generated
2026-06-16
AI Q&A
2026-02-24
EPSS Evaluated
2026-06-14
NVD
CVE-2026-2777
Affected Vendors & Products
Showing 5 associated CPEs
Vendor Product Version / Range
mozilla firefox to 148.0 (exc)
mozilla thunderbird to 148.0 (exc)
mozilla firefox to 115.33.0 (exc)
mozilla firefox From 128.0 (inc) to 140.8.0 (exc)
mozilla thunderbird to 140.8.0 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-269 The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
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Executive Summary

This vulnerability is a privilege escalation issue found in the Messaging System component of Firefox. It affects versions of Firefox earlier than 148, Firefox ESR versions earlier than 115.33, and Firefox ESR versions earlier than 140.8.

Impact Analysis

The vulnerability could allow an attacker to gain elevated privileges within the affected Firefox Messaging System component, potentially enabling unauthorized actions or access beyond what a normal user or process is permitted.

Compliance Impact

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Detection Guidance

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