Firefox JIT Miscompilation in JS Engine, Fixed in 150.0.3
CVE-2026-8389 Published on May 12, 2026

JIT miscompilation in the JavaScript Engine: JIT component
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0.3.

NVD

Vulnerability Analysis

CVE-2026-8389 can be exploited with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. Public availability of a proof of concept (POC) exploit exists for CVE-2026-8389. 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 Types

Function Call With Incorrect Argument Type

The software calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses. This weakness is most likely to occur in loosely typed languages, or in strongly typed languages in which the types of variable arguments cannot be enforced at compilation time, or where there is implicit casting.

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-2026-8389 has been classified to as an Object Type Confusion vulnerability or weakness.

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-2026-8389 has been classified to as a Buffer Overflow vulnerability or weakness.


Products Associated with CVE-2026-8389

Want to know whenever a new CVE is published for Mozilla Firefox? stack.watch will email you.

Mozilla Firefox
 

Affected Versions

Mozilla Firefox:

Exploit Probability

EPSS
0.31%
Percentile
22.10%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.