CVE-2026-74956

Weakness

Same-origin policy bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

Affected products

• mozilla firefox
• mozilla thunderbird

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2032406
• https://www.mozilla.org/security/advisories/mfsa2026-74/
• https://www.mozilla.org/security/advisories/mfsa2026-77/
• https://www.mozilla.org/security/advisories/mfsa2026-78/
• https://www.mozilla.org/security/advisories/mfsa2026-80/