CVE-2026-109772: Same-origin policy bypass in the DevTools component

Published Oct 13, 2026
·
Updated

Same-origin policy bypass in the DevTools component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

Affected Software

2 affected componentsFixes available
Mozilla Firefox<158
158
Mozilla Thunderbird<158
158

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 158
  2. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 158
  3. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 158

Event History

Oct 13, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·12:29 PM
Data Sourced
via MITRE·12:29 PM
Description
Data Sourced
via NVD·01:17 PM
Description

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What update resolves this issue?

The issue was fixed in Firefox 158. Update Mozilla Firefox to version 158 or later.

2

How should this issue be prioritized?

The provided severity is low (1), with a risk score of 5.

Company

Resources

Contact

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