CVE-2026-8970: Privilege escalation in the Security component

Published May 19, 2026
·
Updated

Privilege escalation in the Security component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Affected Software

8 affected componentsFixes available
Mozilla Firefox<151
151
Mozilla Firefox ESR<140.11
140.11
Mozilla Thunderbird<151
151
Mozilla Thunderbird<140.11
140.11
Mozilla Firefox<140.11.0
Mozilla Firefox<151.0.0
Mozilla Thunderbird<140.11
Mozilla Thunderbird<151.0.0

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 151
  2. Upgrade

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

    Fixed in 140.11
  3. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 151
  4. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.11
  5. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 151
  6. Upgrade

    Upgrade Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 140.11

Event History

May 19, 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·12:30 PM
Data Sourced
via MITRE·12:30 PM
Description
Data Sourced
via Red Hat·02:02 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:16 PM
DescriptionSeverityWeaknessAffected Software
Jun 29, 58424
Event
via FIRST·09:08 AM

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2026-8970?

CVE-2026-8970 is classified as a privilege escalation vulnerability in the Security component.

2

How do I fix CVE-2026-8970?

To fix CVE-2026-8970, update to Firefox version 151, Firefox ESR version 140.11, Thunderbird version 151, or Thunderbird ESR version 140.11.

3

What software is affected by CVE-2026-8970?

CVE-2026-8970 affects Mozilla Firefox, Firefox ESR, Mozilla Thunderbird, and Thunderbird ESR prior to specified versions.

4

Is CVE-2026-8970 a critical vulnerability?

While specific severity ratings can vary, privilege escalation vulnerabilities are generally considered serious due to the potential for unauthorized access.

5

Who can exploit CVE-2026-8970?

CVE-2026-8970 can potentially be exploited by attackers who already have access to lower-privileged accounts on the affected software.

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