Description
When Multi-Account Containers was enabled, DNS requests could have bypassed a SOCKS proxy when the domain name was invalid or the SOCKS proxy was not responding. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Affected products
mozilla: firefox
References3
- www.mozilla.org/security/advisories/mfsa2025-51/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=1943804 Permissions Required
- www.mozilla.org/security/advisories/mfsa2025-54/
Metrics
- CVSS 3.1
-
8.6
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L - EPSS — exploit probability
- 0% percentile: 29 · as of 7 November 2026
- CWE
- CWE-200
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