CVE-2026-2779

What it is

Incorrect boundary conditions in the Networking: JAR component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

At a glance

Exploitability

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

Exploit odds

0.7% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2026-02-24 14:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:31 UTC Last updatedMost recent change to the record

Details

Published

2026-02-24 14:16 UTC

Last modified

2026-06-17 10:31 UTC

Exploit probability

0.7% · EPSS, next 30 days

Weakness

CWE-119 · Buffer errors

Record status

Modified

Affected

• Mozilla Firefox < 140.8.0
• Mozilla Firefox < 148.0
• Mozilla Thunderbird < 140.8.0
• Mozilla Thunderbird < 148.0

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