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, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

Affected Software

16 affected componentsFixes available
Mozilla Firefox=156
Firefox ESR=115.41, =140.16, =153.3
Mozilla Firefox<156
156
Mozilla Firefox ESR<153.3
153.3
Mozilla Firefox ESR<140.16
140.16
Mozilla Firefox ESR<115.41
115.41
Mozilla Thunderbird<156
156
Mozilla Thunderbird<140.16
140.16
Mozilla Thunderbird<153.3
153.3
Mozilla Firefox<115.41.0
Mozilla Firefox>=116.0<140.16.0
Mozilla Firefox>=141.0<153.3.0
Mozilla Firefox>=154.0.0<156.0.0
Mozilla Thunderbird<140.16.0
Mozilla Thunderbird>=141.0<153.3.0
Mozilla Thunderbird>=154.0<156.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 156
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 153.3
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 140.16
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 115.41
  5. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird (DOM sandbox escape - Core & HTML) to a version that resolves this vulnerability.

    Fixed in 156
  6. Upgrade

    Upgrade Mozilla Firefox ESR (DOM sandbox escape - Core & HTML) to a version that resolves this vulnerability.

    Fixed in 115.41
  7. Upgrade

    Upgrade Mozilla Firefox ESR (DOM sandbox escape - Core & HTML) to a version that resolves this vulnerability.

    Fixed in 140.16
  8. Upgrade

    Upgrade Mozilla Firefox ESR (DOM sandbox escape - Core & HTML) to a version that resolves this vulnerability.

    Fixed in 153.3
  9. Upgrade

    Upgrade Mozilla Thunderbird (DOM sandbox escape - Core & HTML) to a version that resolves this vulnerability.

    Fixed in 156
  10. Upgrade

    Upgrade Mozilla Thunderbird (DOM sandbox escape - Core & HTML) to a version that resolves this vulnerability.

    Fixed in 140.16
  11. Upgrade

    Upgrade Mozilla Thunderbird (DOM sandbox escape - Core & HTML) to a version that resolves this vulnerability.

    Fixed in 153.3

Event History

Sep 15, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Updated
via Mozilla·12:00 AM
Affected Software
CVE Published
via MITRE·12:33 PM
Data Sourced
via MITRE·12:33 PM
Description
Data Sourced
via NVD·01:16 PM
DescriptionSeverityWeaknessAffected Software
Sep 16, 2026
Updated
via Mozilla·12:00 AM
Affected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

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.

2

Which products should be checked during triage?

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

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203