CVE-2026-83615 xmldom: Quadratic-memory consumption
Attackers can cause denial of service by sending crafted XML that exhausts memory due to quadratic namespace map storage in xmldom.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-83615?
CVE-2026-83615 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 versions 0.1.5 through 0.6.0, appendElement in lib/sax.js uses _copy to clone the complete currentNSMap for each nested element that declares a new namespace prefix. Keeping every ancestor map live on the parse stack creates quadratic peak namespace-map storage, so a small highly compressible XML document can exhaust the process heap 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-770
Which versions are affected by CVE-2026-83615?
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 | From 0.1.5 to 0.6.0 | None |
xmldom npm | From 0.1.5 to 0.6.0 | None |
How do I fix CVE-2026-83615?
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-2026-83615 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-83615 exists.
Sources
Also known as AZL-99359, CLEANSTART-2026-TN18132, DEBIAN-CVE-2026-83615, ECHO-93d3-ae75-ca31, GHSA-965w-775f-mr7g, MINI-4464-m24h-9x7v and 5 more.