CVE-2026-74960: Site isolation issue in the WebExtensions component
Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 140.14 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 154 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 153.1 - Upgrade
Upgrade
Firefox WebExtensionsto a version that resolves this vulnerability.Fixed in 154 - Upgrade
Upgrade
Firefox ESR WebExtensionsto a version that resolves this vulnerability.Fixed in 140.14 - Upgrade
Upgrade
Firefox ESR WebExtensionsto a version that resolves this vulnerability.Fixed in 153.1
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
- CVE-2026-74934
- CVE-2026-74935
- CVE-2026-74936
- CVE-2026-74939
- CVE-2026-74940
- CVE-2026-74941
- CVE-2026-74942
- CVE-2026-74943
- CVE-2026-74944
- CVE-2026-74945
- CVE-2026-74946
- CVE-2026-74948
- CVE-2026-74949
- CVE-2026-74953
- CVE-2026-74957
- CVE-2026-74959
- CVE-2026-74960
- CVE-2026-74962
- CVE-2026-74963
- CVE-2026-74964
- CVE-2026-74965
- CVE-2026-74967
- CVE-2026-74969
- CVE-2026-74971
- CVE-2026-74972
- CVE-2026-74973
- CVE-2026-74974
- CVE-2026-74976
- CVE-2026-74983
- CVE-2026-74987
- CVE-2026-74990
- CVE-2026-75874
- CVE-2026-74937
- CVE-2026-74938
- CVE-2026-74947
- CVE-2026-74950
- CVE-2026-74951
- CVE-2026-74952
- CVE-2026-74954
- CVE-2026-74955
- CVE-2026-74956
- CVE-2026-74958
- CVE-2026-74961
- CVE-2026-74966
- CVE-2026-74968
- CVE-2026-74970
- CVE-2026-74975
- CVE-2026-74977
- CVE-2026-74978
- CVE-2026-74979
- CVE-2026-74980
- CVE-2026-74981
- CVE-2026-74982
- CVE-2026-74984
- CVE-2026-74985
- CVE-2026-74986
- CVE-2026-74988
- CVE-2026-74989
Frequently Asked Questions
Which releases contain the fix?
The issue is fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. Install the applicable fixed release for the Firefox or Firefox ESR branch in use.