Certain Neko-related HTML parsers allow a denial of service via crafted Processing Instruction (PI) input that causes excessive heap memory consumption. In particular, this issue exists in HtmlUnit-Neko through 2.26, and is fixed in 2.27. This issue also exists in CyberNeko HTML through 1.9.22 (also affecting OWASP AntiSamy before 1.6.6), but 1.9.22 is the last version of CyberNeko HTML. NOTE: this may be related to CVE-2022-24839.

org.cyberneko.html is an html parser written in Java. The fork of `org.cyberneko.html` used by Nokogiri (Rubygem) raises a `java.lang.OutOfMemoryError` exception when parsing ill-formed HTML markup. Users are advised to upgrade to `>= 1.9.22.noko2`. Note: The upstream library `org.cyberneko.html` is no longer maintained. Nokogiri uses its own fork of this library located at https://github.com/sparklemotion/nekohtml and this CVE applies only to that fork. Other forks of nekohtml may have a similar vulnerability.