Firefox JIT Miscompilation in DOM Core & HTML (before 152, ESR 140.12, 115.37)
CVE-2026-12299 Published on June 16, 2026

JIT miscompilation in the DOM: Core & HTML component
JIT miscompilation in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

NVD

Vulnerability Analysis

CVE-2026-12299 can be exploited 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 have a small impact on confidentiality and integrity, and no impact on availability.

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

Weakness Type

What is an Object Type Confusion Vulnerability?

The program allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

CVE-2026-12299 has been classified to as an Object Type Confusion vulnerability or weakness.


Products Associated with CVE-2026-12299

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Mozilla Firefox
 
Mozilla Thunderbird
 

Affected Versions

Mozilla Firefox: Mozilla Thunderbird: