CVE-2026-12326

Modified Modified - Updated After Analysis

Memory Corruption in Firefox and Thunderbird

Publication date: 2026-06-16

Last updated on: 2026-06-30

Assigner: Mozilla Corporation

Description

Memory safety bugs present in Firefox 151 and Thunderbird 151. 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 152 and Thunderbird 152.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-06-16

Last Modified

2026-06-30

Generated

2026-07-06

AI Q&A

2026-06-16

EPSS Evaluated

2026-07-05

NVD

CVE-2026-12326

EUVD

EUVD-2026-37072

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	to 152 (exc)
mozilla	thunderbird	151

Helpful Resources

Exploitability

CWE

KEV

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.
CWE-825	The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.

Attack-Flow Graph

Executive Summary

This vulnerability involves memory safety bugs found in Firefox 151 and Thunderbird 151. Some of these bugs showed evidence of memory corruption, which means that the program's memory could be improperly accessed or modified. It is presumed that with enough effort, these bugs could have been exploited to run arbitrary code, potentially allowing an attacker to execute malicious actions on the affected system. The issue was fixed in Firefox 152.

Impact Analysis

The vulnerability could allow an attacker to exploit memory corruption bugs to run arbitrary code on your system through Firefox 151 or Thunderbird 151. This could lead to unauthorized actions such as installing malware, stealing data, or taking control of your device. Using updated versions like Firefox 152 mitigates this risk.

Mitigation Strategies

The vulnerability was fixed in Firefox 152. To mitigate this vulnerability, you should update your Firefox and Thunderbird installations to version 152 or later.

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