CVE-2026-92018: Sandbox escape in the DOM: Core & HTML component

Published Sep 15, 2026

Updated

Sandbox escape in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.

Affected Software

2 affected components

Mozilla Firefox=156

Firefox ESR=115.41, =140.16, =153.3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Mozilla Firefox (Core & HTML component) to a version that resolves this vulnerability.
Fixed in 156
Upgrade
Upgrade Mozilla Firefox ESR (Core & HTML component) to a version that resolves this vulnerability.
Fixed in 115.41
Upgrade
Upgrade Mozilla Firefox ESR (Core & HTML component) to a version that resolves this vulnerability.
Fixed in 140.16
Upgrade
Upgrade Mozilla Firefox ESR (Core & HTML component) 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 vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.

Which products should be checked during triage?

Check Mozilla Firefox and Firefox ESR installations against the fixed release versions.