CVE-2026-92015

What it is

Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

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, service disruption.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2026-09-15 13:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-06 14:45 UTC Last updatedMost recent change to the record

Details

Published

2026-09-15 13:16 UTC

Last modified

2026-10-06 14:45 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-269 · Improper privilege management

Record status

Analyzed

Affected

• Mozilla Firefox < 115.41.0
• Mozilla Firefox < 140.16.0
• Mozilla Firefox < 153.3.0
• Mozilla Firefox < 156.0.0
• Mozilla Thunderbird < 140.16.0
• Mozilla Thunderbird < 153.3.0
• Mozilla Thunderbird < 156.0

Attack profile CVSS 3.1 · 8.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High