CVE-2026-8974
Modified Modified - Updated After Analysis
Memory Corruption in Firefox ESR and Firefox

Publication date: 2026-05-19

Last updated on: 2026-05-26

Assigner: Mozilla Corporation

Description
Memory safety bugs present in Firefox ESR 140.10 and Firefox 150. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. 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
2026-05-26
Generated
2026-06-10
AI Q&A
2026-05-19
EPSS Evaluated
2026-06-08
NVD
CVE-2026-8974
EUVD
EUVD-2026-30922
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 140.11 (exc)
mozilla thunderbird to 151.0.0 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-119 The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
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Executive Summary

This vulnerability involves memory safety bugs found in Firefox ESR 140.10 and Firefox 150. Some of these bugs showed evidence of memory corruption, which means that they could potentially be exploited to execute arbitrary code on the affected system.

The issue was addressed and fixed in Firefox 151 and Firefox ESR 140.11.

Impact Analysis

If exploited, this vulnerability could allow an attacker to run arbitrary code on your system through the affected versions of Firefox. This could lead to unauthorized actions, data compromise, or system control by the attacker.

Mitigation Strategies

To mitigate this vulnerability, update Firefox to version 151 or later, or Firefox ESR to version 140.11 or later, where the memory safety bugs have been fixed.

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