CVE-2026-8955
Modified Modified - Updated After Analysis
Privilege Escalation in Firefox DOM Workers

Publication date: 2026-05-19

Last updated on: 2026-05-20

Assigner: Mozilla Corporation

Description
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
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Meta Information
Published
2026-05-19
Last Modified
2026-05-20
Generated
2026-06-10
AI Q&A
2026-05-19
EPSS Evaluated
2026-06-08
NVD
CVE-2026-8955
EUVD
EUVD-2026-30905
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
mozilla firefox to 151.0.0 (exc)
mozilla firefox to 140.11.0 (exc)
mozilla thunderbird to 151.0.0 (exc)
mozilla thunderbird to 140.11 (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 in the DOM: Workers component of Mozilla Firefox. It allows an attacker to gain higher privileges than intended within the browser environment. The issue was addressed and fixed in Firefox version 151 and Firefox ESR 140.11.

Impact Analysis

The vulnerability could allow an attacker to escalate their privileges within the browser, potentially enabling them to execute actions or access data that should be restricted. This could lead to unauthorized access or manipulation of browser processes or user data.

Mitigation Strategies

To mitigate this privilege escalation vulnerability in the DOM: Workers component, you should update your Firefox browsers to version 151 or later, and Firefox ESR to version 140.11 or later.

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