CVE-2026-4700
CRITICALMitigation bypass in the Networking: HTTP component
Title source: cnaDescription
Mitigation bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Scores
CVSS v3
9.8
EPSS
0.0002
EPSS Percentile
6.6%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
total
Details
CWE
CWE-288
Status
published
Products (10)
mozilla/firefox
< 140.9.0
mozilla/firefox
< 149.0
Mozilla/Firefox
140.9 - 140.*
Mozilla/Firefox
149
Mozilla/Firefox
unspecified - 149
Mozilla/Firefox ESR
unspecified - 140.9
Mozilla/Thunderbird
140.9 - 140.*
Mozilla/Thunderbird
149
Mozilla/Thunderbird
unspecified - 140.9
Mozilla/Thunderbird
unspecified - 149
Published
Mar 24, 2026
Tracked Since
Mar 24, 2026