Description
wp_kses_bad_protocol in wp-includes/kses.php in WordPress before 5.3.1 mishandles the HTML5 colon named entity, allowing attackers to bypass input sanitization, as demonstrated by the javascript: substring.
References (6)
Core 6
Core References
Release Notes, Vendor Advisory x_refsource_misc
https://wordpress.org/news/2019/12/wordpress-5-3-1-security-and-maintenance-release/
Patch x_refsource_misc
https://github.com/WordPress/wordpress-develop/commit/b1975463dd995da19bb40d3fa0786498717e3c53
Mailing List, Third Party Advisory mailing-list
x_refsource_bugtraq
https://seclists.org/bugtraq/2020/Jan/8
Third Party Advisory vendor-advisory
x_refsource_debian
https://www.debian.org/security/2020/dsa-4599
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2020/01/msg00010.html
Third Party Advisory vendor-advisory
x_refsource_debian
https://www.debian.org/security/2020/dsa-4677
Scores
CVSS v3
9.8
EPSS
0.0137
EPSS Percentile
80.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Details
CWE
CWE-20
Status
published
Products (4)
debian/debian_linux
8.0
debian/debian_linux
9.0
debian/debian_linux
10.0
wordpress/wordpress
< 5.3.1
Published
Dec 27, 2019
Tracked Since
Feb 18, 2026