jsoup through 1.23.2, fixed in commit 862ba2f, contains an uncontrolled resource consumption vulnerability in XmlTreeBuilder that allows remote attackers to exhaust JVM heap memory by supplying a deeply nested XML document with uniquely-namespaced elements. The builder copies the entire inherited namespace map on every start element, causing quadratic time and memory complexity, which attackers can exploit to trigger an OutOfMemoryError and terminate the application.

jsoup is a Java HTML parser, built for HTML editing, cleaning, scraping, and cross-site scripting (XSS) safety. jsoup may incorrectly sanitize HTML including javascript: URL expressions, which could allow XSS attacks when a reader subsequently clicks that link. If the non-default SafeList.preserveRelativeLinks option is enabled, HTML including javascript: URLs that have been crafted with control characters will not be sanitized. If the site that this HTML is published on does not set a Content Security Policy, an XSS attack is then possible. This issue is patched in jsoup 1.15.3. Users should upgrade to this version. Additionally, as the unsanitized input may have been persisted, old content should be cleaned again using the updated version. To remediate this issue without immediately upgrading: - disable SafeList.preserveRelativeLinks, which will rewrite input URLs as absolute URLs - ensure an appropriate Content Security Policy is defined. (This should be used regardless of upgrading, as a defence-in-depth best practice.)

Crafted input may cause the jsoup HTML and XML parser to get stuck, timeout, or throw unchecked exceptions