CVE-2026-92023: Use-after-free in the XML component

Q: Which Firefox releases contain the fix?

The issue was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.

Q: How can I determine whether a Firefox installation remains affected?

Compare the installed Firefox or Firefox ESR version with the fixed release for its release line. Installations below Firefox 156, ESR 115.41, ESR 140.16, or ESR 153.3 have not received the listed fix.

Published Sep 15, 2026

Updated

Use-after-free in the XML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.

Affected Software

4 affected components

Mozilla Firefox<156

Mozilla Firefox ESR 115<115.41

Mozilla Firefox ESR 140<140.16

Mozilla Firefox ESR 153<153.3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Mozilla Firefox to a version that resolves this vulnerability.
Fixed in 156
Upgrade
Upgrade Mozilla Firefox ESR to a version that resolves this vulnerability.
Fixed in 115.41
Upgrade
Upgrade Mozilla Firefox ESR to a version that resolves this vulnerability.
Fixed in 140.16
Upgrade
Upgrade Mozilla Firefox ESR to a version that resolves this vulnerability.
Fixed in 153.3

Event History

Sep 15, 2026

CVE Published

via MITRE·12:33 PM

Data Sourced

via MITRE·12:33 PM

Description

Frequently Asked Questions

Which Firefox releases contain the fix?

The issue was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.

How can I determine whether a Firefox installation remains affected?