WordPress before 5.2.4 has a Server Side Request Forgery (SSRF) vulnerability because URL validation does not consider the interpretation of a name as a series of hex characters.
blog.wpscan.org/wordpress/security/release/2019/10/15/wordpress-524-security-release-breakdown.html
core.trac.wordpress.org/changeset/46475
github.com/WordPress/WordPress/commit/608d39faed63ea212b6c6cdf9fe2bef92e2120ea
lists.debian.org/debian-lts-announce/2019/11/msg00000.html
seclists.org/bugtraq/2020/Jan/8
wordpress.org/news/2019/10/wordpress-5-2-4-security-release/
wpvulndb.com/vulnerabilities/9912
www.debian.org/security/2020/dsa-4599
www.debian.org/security/2020/dsa-4677