CVE-2021-4140
CRITICALFirefox ESR < 91.5, Firefox < 96, Thunderbird < 91.5 - XSS
Title source: llmDescription
It was possible to construct specific XSLT markup that would be able to bypass an iframe sandbox. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.
References (4)
Core 4
Core References
Exploit, Issue Tracking, Patch, Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1746720
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2022-01/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2022-02/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2022-03/
Scores
CVSS v3
10.0
EPSS
0.0135
EPSS Percentile
67.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
total
Details
CWE
CWE-91
Status
published
Products (3)
mozilla/firefox
< 96.0
mozilla/firefox_esr
< 91.5
mozilla/thunderbird
< 91.5
Published
Dec 22, 2022
Tracked Since
Feb 18, 2026