CVE-2026-92055

Received Received - Intake

Privilege Escalation in Firefox DevTools

Publication date: 2026-09-15

Last updated on: 2026-10-05

Assigner: Mozilla Corporation

Description

Privilege escalation in the DevTools component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, and Thunderbird 156.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-15

Last Modified

2026-10-05

Generated

2026-10-05

AI Q&A

2026-09-15

EPSS Evaluated

2026-10-04

NVD

CVE-2026-92055

EUVD

EUVD-2026-78518

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	thunderbird	From 154.0 (inc) to 156.0 (exc)
mozilla	firefox	to 153.3.0 (exc)
mozilla	firefox	From 154.0.0 (inc) to 156.0.0 (exc)
mozilla	thunderbird	to 153.3.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

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.

Attack-Flow Graph

Executive Summary

This is a privilege escalation vulnerability in Firefox's DevTools component. It allows an attacker with limited access to gain higher privileges, potentially taking control of the browser or executing arbitrary code. The issue was patched in Firefox 156 and Firefox ESR 153.3.

Detection Guidance

To detect this vulnerability, check the installed version of Firefox or Firefox ESR. Compare it against the fixed versions (Firefox 156 or Firefox ESR 153.3). Use commands like 'firefox --version' or 'apt list --installed | grep firefox' on Linux systems.

Impact Analysis

If exploited, this vulnerability could let an attacker with basic user access escalate privileges, steal sensitive data, install malware, or monitor your activities. Users running unpatched versions of Firefox are at risk.

Compliance Impact

The vulnerability allows privilege escalation through the DevTools component, which could lead to unauthorized access to sensitive data. This may impact compliance with GDPR by potentially exposing personal data and HIPAA by compromising protected health information if exploited.

Mitigation Strategies

Immediately update Firefox to version 156 or Firefox ESR to version 153.3 or later. Disable DevTools if not required. Regularly monitor for updates from Mozilla to ensure ongoing protection.

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