CVE-2026-4698

What it is

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-03-24 13:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-15 02:22 UTC Last updatedMost recent change to the record

Details

Published

2026-03-24 13:16 UTC

Last modified

2026-07-15 02:22 UTC

Exploit probability

0.8% · EPSS, next 30 days

Weakness

CWE-843

Record status

Modified

Affected

• Mozilla Firefox < 115.34.0
• Mozilla Firefox < 149.0
• Mozilla Firefox < 140.9.0

Attack profile CVSS 3.1 · 9.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High