Firefox Memory Safety Bugs 140.10/150: Arbitrary Code Exec Fix in 151
CVE-2026-8974 Published on May 19, 2026

Memory safety bugs fixed in Firefox ESR 140.11 and Firefox 151
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.

NVD

Vulnerability Analysis

CVE-2026-8974 is exploitable with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a Buffer Overflow Vulnerability?

The software performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer.

CVE-2026-8974 has been classified to as a Buffer Overflow vulnerability or weakness.


Products Associated with CVE-2026-8974

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Mozilla Firefox
 
Mozilla Thunderbird
 

Affected Versions

Mozilla Firefox: Mozilla Thunderbird: