CVE-2026-83616 xmldom: Processing Instruction Target Injection Bypasses requireWellFormed
Attackers can inject XML structure via unvalidated processing instruction targets in xmldom, potentially leading to code execution or data exposure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-83616?
CVE-2026-83616 is a high-severity 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, Document.createProcessingInstruction(target, data) in lib/dom.js accepts an unvalidated target, while the requireWellFormed: true serializer checks only for a colon and the reserved case-insensitive xml name on 0.9.x and performs no target check on 0.8.x. Because serialization emits <?target data?>, a target containing >, ?, whitespace, or another invalid XML-name character can break the processing-instruction boundary and inject XML structure. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.
Weakness: CWE-91
Which versions are affected by CVE-2026-83616?
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-2026-83616?
Upgrade @xmldom/xmldom to a fixed version for your release line: 0.8.15 or 0.9.12.
Is CVE-2026-83616 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-83616 exists.
Sources
Also known as AZL-99351, CLEANSTART-2026-RE03719, DEBIAN-CVE-2026-83616, ECHO-7609-7091-30d9, GHSA-c7q8-3ch8-vqpv, MINI-627v-m97x-c64h and 5 more.