CVE-2026-74955: Privilege escalation in the Request Handling component
Privilege escalation in the Request Handling component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 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 154 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 153.1 - Upgrade
Upgrade
Firefox / Firefox ESR / Thunderbirdto a version that resolves this vulnerability.Fixed in 154 - Upgrade
Upgrade
Firefox / Firefox ESR / Thunderbirdto 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-2026-75874
- CVE-2026-74934
- CVE-2026-74935
- CVE-2026-74936
- CVE-2026-74937
- CVE-2026-74938
- 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-2026-74947
- CVE-2026-74948
- CVE-2026-74949
- CVE-2026-74950
- CVE-2026-74951
- CVE-2026-74952
- CVE-2026-74953
- CVE-2026-74954
- CVE-2026-74955
- CVE-2026-74956
- CVE-2026-74957
- CVE-2026-74958
- CVE-2026-74959
- CVE-2026-74960
- CVE-2026-74961
- CVE-2026-74962
- CVE-2026-74963
- CVE-2026-74964
- CVE-2026-74965
- CVE-2026-74966
- CVE-2026-74967
- CVE-2026-74968
- CVE-2026-74969
- CVE-2026-74970
- CVE-2026-74971
- CVE-2026-74972
- CVE-2026-74973
- CVE-2026-74974
- CVE-2026-74975
- CVE-2026-74976
- CVE-2026-74977
- CVE-2026-74978
- CVE-2026-74979
- CVE-2026-74980
- CVE-2026-74981
- CVE-2026-74982
- CVE-2026-74983
- CVE-2026-74984
- CVE-2026-74985
- CVE-2026-74986
- CVE-2026-74987
- CVE-2026-74988
- CVE-2026-74989
- CVE-2026-74990
- CVE-2026-84637
Frequently Asked Questions
Which Firefox releases contain the fix?
Mozilla states that the issue is fixed in Firefox 154 and Firefox ESR 153.1. Systems running those versions or later include the fix.