CVE-2019-11763
MEDIUMFirefox <70, Thunderbird <68.2, Firefox ESR <68.2 - XSS
Title source: llmDescription
Failure to correctly handle null bytes when processing HTML entities resulted in Firefox incorrectly parsing these entities. This could have led to HTML comment text being treated as HTML which could have led to XSS in a web application under certain conditions. It could have also led to HTML entities being masked from filters - enabling the use of entities to mask the actual characters of interest from filters. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
References (6)
Core 6
Core References
Vendor Advisory x_refsource_confirm
https://www.mozilla.org/security/advisories/mfsa2019-35/
Vendor Advisory x_refsource_confirm
https://www.mozilla.org/security/advisories/mfsa2019-33/
Vendor Advisory x_refsource_confirm
https://www.mozilla.org/security/advisories/mfsa2019-34/
Issue Tracking, Permissions Required x_refsource_confirm
https://bugzilla.mozilla.org/show_bug.cgi?id=1584216
Third Party Advisory vendor-advisory
x_refsource_gentoo
https://security.gentoo.org/glsa/202003-10
Third Party Advisory vendor-advisory
x_refsource_ubuntu
https://usn.ubuntu.com/4335-1/
Scores
CVSS v3
6.1
EPSS
0.0176
EPSS Percentile
82.9%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Details
CWE
CWE-79
Status
published
Products (4)
canonical/ubuntu_linux
16.04
mozilla/firefox
< 70.0
mozilla/firefox_esr
< 68.2
mozilla/thunderbird
< 68.2
Published
Jan 08, 2020
Tracked Since
Feb 18, 2026