CVE-2019-11763

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.

• CWE-79

• https://bugzilla.mozilla.org/show_bug.cgi?id=1584216Issue Tracking, Permissions Required
• https://security.gentoo.org/glsa/202003-10Third Party Advisory
• https://usn.ubuntu.com/4335-1/Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-33/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-34/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-35/Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1584216Issue Tracking, Permissions Required
• https://security.gentoo.org/glsa/202003-10Third Party Advisory
• https://usn.ubuntu.com/4335-1/Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-33/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-34/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-35/Vendor Advisory

Published

Jan 8, 2020

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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