CVE-2026-83617

xmldom is a JavaScript module implementing DOMParser and XMLSerializer. In versions from 0.7.0 to 0.8.15, the parser in lib/sax.js uses an unanchored global expression to trim end-tag names, leading to quadratic backtracking on long whitespace runs. A small unauthenticated XML document can stall the Node.js event loop. This issue is fixed in version 0.8.15.

xmldom is a JavaScript module implementing DOMParser and XMLSerializer. In versions from 0.9.10 to 0.9.12, validation of DocumentType.publicId and systemId using expressions with the multiline flag allows bypassing validation and injecting markup into the <!DOCTYPE> declaration. This issue is fixed in version 0.9.12.

xmldom is a JavaScript module implementing DOMParser and XMLSerializer. Prior to versions 0.8.15 and 0.9.12, and in xmldom 0.6.0 and earlier, Document.createProcessingInstruction() accepts an unvalidated target, allowing XML structure injection by breaking the processing-instruction boundary. This issue is fixed in versions 0.8.15 and 0.9.12; no fix is available for xmldom.

xmldom is a JavaScript module implementing DOMParser and XMLSerializer. Prior to versions 0.8.15 and 0.9.12, and in xmldom 0.1.5-0.6.0, appendElement in lib/sax.js clones the entire namespace map for each nested element, leading to quadratic memory usage. A small XML document can exhaust the process heap. This issue is fixed in versions 0.8.15 and 0.9.12; no fix is available for xmldom.

xmldom is a JavaScript module implementing DOMParser and XMLSerializer. Prior to versions 0.8.15 and 0.9.12, and in xmldom 0.3.0-0.6.0, two independent quadratic paths can cause denial of service: parseElementStartPart repeatedly rescans a malformed tag name, and normalize() repeatedly removes and appends adjacent text nodes. This issue is fixed in versions 0.8.15 and 0.9.12; no fix is available for xmldom.

xmldom is a JavaScript module implementing DOMParser and XMLSerializer. Prior to versions 0.8.15 and 0.9.12, and in xmldom 0.6.0 and earlier, DOMHandler.startElement inserts every attribute through setAttributeNode, and NamedNodeMap.setNamedItem performs a linear lookup, leading to quadratic complexity with many attributes. A small XML document can stall the Node.js event loop. This issue is fixed in versions 0.8.15 and 0.9.12; no fix is available for xmldom.

xmldom is a JavaScript module implementing DOMParser and XMLSerializer. In versions from 0.9.0-beta.1 to 0.9.12, HTML-mode parsing through DOMParser.parseFromString() mishandles mixed-case closing tags for script, style, textarea, and title elements. This leads to unstable parser progression and quadratic output amplification. A small text/html document can consume disproportionate CPU and memory. This issue is fixed in version 0.9.12.

The @xmldom/xmldom library before versions 0.9.10 and 0.8.13 and xmldom version 0.6.0 and earlier fail to validate processing instruction data, allowing an attacker to inject the closing sequence ?> and add arbitrary XML nodes to the resulting document.

In @xmldom/xmldom prior to versions 0.9.10 and 0.8.13 and xmldom version 0.6.0 and earlier, seven recursive traversals in lib/dom.js operate without a depth limit. A sufficiently deeply nested DOM tree causes a RangeError: Maximum call stack size exceeded, crashing the application.