CVE-2026-6755

Description

Mitigation bypass in the DOM: postMessage component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVSS Vector

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1880429
• https://www.mozilla.org/security/advisories/mfsa2026-30/
• https://www.mozilla.org/security/advisories/mfsa2026-33/