CVE-2026-4729
Received Received - Intake
Memory Corruption in Firefox and Thunderbird <149 Enables Code Execution

Publication date: 2026-03-24

Last updated on: 2026-04-13

Assigner: Mozilla Corporation

Description
Memory safety bugs present in Firefox 148 and Thunderbird 148. 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 149 and Thunderbird 149.
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Meta Information
Published
2026-03-24
Last Modified
2026-04-13
Generated
2026-06-16
AI Q&A
2026-03-24
EPSS Evaluated
2026-06-15
NVD
CVE-2026-4729
EUVD
EUVD-2026-14873
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
mozilla firefox to 149.0 (exc)
mozilla thunderbird to 149.0 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-120 The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
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Executive Summary

This vulnerability involves memory safety bugs found in Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption, which means that the software could access or modify memory in unintended ways. It is presumed that with enough effort, some of these bugs could have been exploited to run arbitrary code on the affected systems.

Impact Analysis

If exploited, this vulnerability could allow an attacker to execute arbitrary code on your system through Firefox or Thunderbird versions prior to 149. This could lead to unauthorized actions such as installing malware, stealing data, or taking control of your device.

Compliance Impact

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