Description
An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Scores
CVSS v3
9.1
EPSS
0.0032
EPSS Percentile
54.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
total
Details
CWE
CWE-693
Status
published
Products (3)
mozilla/firefox
< 140.0
Mozilla/Firefox
140
Mozilla/Thunderbird
140
Published
Jun 24, 2025
Tracked Since
Feb 18, 2026