CVE-2026-12290

What it is

Memory safety bug fixed in Thunderbird 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2026-06-16 13:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-26 11:10 UTC Last updatedMost recent change to the record

Details

Published

2026-06-16 13:16 UTC

Last modified

2026-10-26 11:10 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-119 · Buffer errors

Record status

Modified

Affected

• Mozilla Firefox < 115.37.0
• Mozilla Firefox < 152.0.0
• Mozilla Firefox < 140.12.0
• Mozilla Thunderbird < 152.0.0
• Mozilla Thunderbird < 140.12.0

Attack profile CVSS 3.1 · 8.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None