CVE-2026-83613 xmldom: Quadratic-time attribute deduplication
Attackers can cause denial of service in Node.js applications using xmldom by submitting XML with many attributes, triggering quadratic time complexity.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-83613?
CVE-2026-83613 is a high-severity denial of service vulnerability in @xmldom xmldom, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.15 and 0.9.12, and in xmldom version 0.6.0 and earlier, DOMHandler.startElement in lib/dom-parser.js inserts every parsed attribute through setAttributeNode, while NamedNodeMap.setNamedItem in lib/dom.js calls the linear getNamedItem or getNamedItemNS lookup for each insertion. A well-formed element with many distinct attributes therefore requires quadratic comparisons during DOMParser.parseFromString() and can stall a Node.js event loop before application validation. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.
Weakness: CWE-407
Which versions are affected by CVE-2026-83613?
6 open source packages ship an affected version, including @xmldom/xmldom and xmldom.
| Package | Affected | Fixed in |
|---|---|---|
@xmldom/xmldom npm | From 0.7.0 | 0.8.15 |
@xmldom/xmldom npm | From 0.7.0 | 0.8.15 |
@xmldom/xmldom npm | From 0.9.0 | 0.9.12 |
@xmldom/xmldom npm | From 0.9.0 | 0.9.12 |
xmldom npm | All versions to 0.6.0 | None |
xmldom npm | All versions to 0.6.0 | None |
How do I fix CVE-2026-83613?
Upgrade @xmldom/xmldom to a fixed version for your release line: 0.8.15 or 0.9.12.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-83613 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-83613 exists.
Sources
Also known as AZL-99353, CLEANSTART-2026-OV26495, DEBIAN-CVE-2026-83613, ECHO-ea52-9ef9-83eb, GHSA-8344-3jmq-59r6, MINI-335q-pf9f-r9rj and 5 more.