CVE-2026-92019: Mitigation bypass in the Remote Settings Client component

Published Sep 15, 2026
·
Updated

Mitigation bypass in the Remote Settings Client 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

15 affected componentsFixes available
Mozilla Firefox<156, <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 (Remote Settings Client) to a version that resolves this vulnerability.

    Fixed in 156
  6. Upgrade

    Upgrade Mozilla Firefox ESR (Remote Settings Client) to a version that resolves this vulnerability.

    Fixed in 115.41
  7. Upgrade

    Upgrade Mozilla Firefox ESR (Remote Settings Client) to a version that resolves this vulnerability.

    Fixed in 140.16
  8. Upgrade

    Upgrade Mozilla Firefox ESR (Remote Settings Client) to a version that resolves this vulnerability.

    Fixed in 153.3
  9. Upgrade

    Upgrade Mozilla Thunderbird (Remote Settings Client) to a version that resolves this vulnerability.

    Fixed in 156
  10. Upgrade

    Upgrade Mozilla Thunderbird (Remote Settings Client) to a version that resolves this vulnerability.

    Fixed in 140.16
  11. Upgrade

    Upgrade Mozilla Thunderbird (Remote Settings Client) 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
CVE Published
via MITRE·12:33 PM
Data Sourced
via MITRE·12:33 PM
Description
Data Sourced
via NVD·01:16 PM
DescriptionSeverityWeaknessAffected 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 issue was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.

Company

Resources

Contact

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