DOMPurify 3.1.3 through 3.3.1 and 2.5.3 through 2.5.8, fixed in commit 2726c74, contain a cross-site scripting vulnerability that allows attackers to bypass attribute sanitization by exploiting five missing rawtext elements (noscript, xmp, noembed, noframes, iframe) in the SAFEFORXML regex. Attackers can include payloads like /noscriptimg src=x onerror=alert(1) in attribute values to execute JavaScript when sanitized output is placed inside these unprotected rawtext contexts.

DOMPurify 3.1.3 through 3.2.6 and 2.5.3 through 2.5.8 contain a cross-site scripting vulnerability that allows attackers to bypass attribute sanitization by exploiting missing textarea rawtext element validation in the SAFEFORXML regex. Attackers can include closing rawtext tags like /textarea in attribute values to break out of rawtext contexts and execute JavaScript when sanitized output is placed inside rawtext elements. The 3.x branch was fixed in 3.2.7; the 2.x branch was never patched.

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions prior to 3.4.0 have an inconsistency between FORBIDTAGS and FORBIDATTR handling when function-based ADDTAGS is used. Commit c361baa added an early exit for FORBIDATTR at line 1214. The same fix was not applied to FORBIDTAGS. At line 1118-1123, when EXTRAELEMENTHANDLING.tagCheck returns true, the short-circuit evaluation skips the FORBIDTAGS check entirely. This allows forbidden elements to survive sanitization with their attributes intact. Version 3.4.0 patches the issue.

DOMPurify before 3.4.13 contains a cross-site scripting vulnerability in INPLACE sanitization where element-removal hooks fail to neutralize detached subtrees. Attackers can supply HTML with event handlers on descendant elements that execute after sanitization completes, even though the returned root appears clean.

DOMPurify before 3.3.2 contains a mutation-XSS vulnerability when sanitized HTML is reinserted into special parsing contexts using innerHTML with wrappers like script, xmp, iframe, noembed, noframes, or noscript. Attackers can craft payloads with closing sequences that break out of the wrapper context during reparsing, reactivating dangerous markup with event handlers to execute JavaScript.

DOMPurify before 3.2.4 has an incorrect template literal regular expression, sometimes leading to mutation cross-site scripting (mXSS).