vulnerability / NVI-00014095 / Revision 1
xmldom: Element name injection via createElement() bypasses requireWellFormed
GitHub lists this reviewed advisory for @xmldom/xmldom, @xmldom/xmldom, xmldom. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
@xmldom/xmldom
source listed>= 0.9.0, <= 0.9.10
## Summary `Document.createElement()` in `@xmldom/xmldom` accepts arbitrary strings as the `tagName` parameter with zero validation. The serializer emits the tag name verbatim into XML/HTML output. Critically, the `requireWellFormed: true` serializer option — the recommended mitigation from CVE-2026-41672, CVE-2026-41674, and CVE-2026-34601 — did NOT catch this, making it a bypass of the existing security controls. An attacker who controls the element name string can inject arbitrary attributes (including event handlers) into the serialized output, leading to XSS when the output is consumed by a browser or downstream parser. ## Details `Document.createElement()` accepts any string as `tagName` and stores it directly on the element node without validation. When the document is later serialized via `XMLSerializer.serializeToString()`, the serializer emits the `tagName` verbatim into the output. The XML specification requires element names to conform to the `Name` production. The existing `createAttributeNS()` and `createElementNS()` methods validate qualified names against an anchored name/`QName` pattern, but `createElement()` bypasses this entirely, and the `requireWellFormed:
@xmldom/xmldom
source listed>= 0.7.0, <= 0.8.13
## Summary `Document.createElement()` in `@xmldom/xmldom` accepts arbitrary strings as the `tagName` parameter with zero validation. The serializer emits the tag name verbatim into XML/HTML output. Critically, the `requireWellFormed: true` serializer option — the recommended mitigation from CVE-2026-41672, CVE-2026-41674, and CVE-2026-34601 — did NOT catch this, making it a bypass of the existing security controls. An attacker who controls the element name string can inject arbitrary attributes (including event handlers) into the serialized output, leading to XSS when the output is consumed by a browser or downstream parser. ## Details `Document.createElement()` accepts any string as `tagName` and stores it directly on the element node without validation. When the document is later serialized via `XMLSerializer.serializeToString()`, the serializer emits the `tagName` verbatim into the output. The XML specification requires element names to conform to the `Name` production. The existing `createAttributeNS()` and `createElementNS()` methods validate qualified names against an anchored name/`QName` pattern, but `createElement()` bypasses this entirely, and the `requireWellFormed:
xmldom
source listed<= 0.6.0
## Summary `Document.createElement()` in `@xmldom/xmldom` accepts arbitrary strings as the `tagName` parameter with zero validation. The serializer emits the tag name verbatim into XML/HTML output. Critically, the `requireWellFormed: true` serializer option — the recommended mitigation from CVE-2026-41672, CVE-2026-41674, and CVE-2026-34601 — did NOT catch this, making it a bypass of the existing security controls. An attacker who controls the element name string can inject arbitrary attributes (including event handlers) into the serialized output, leading to XSS when the output is consumed by a browser or downstream parser. ## Details `Document.createElement()` accepts any string as `tagName` and stores it directly on the element node without validation. When the document is later serialized via `XMLSerializer.serializeToString()`, the serializer emits the `tagName` verbatim into the output. The XML specification requires element names to conform to the `Name` production. The existing `createAttributeNS()` and `createElementNS()` methods validate qualified names against an anchored name/`QName` pattern, but `createElement()` bypasses this entirely, and the `requireWellFormed:
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-w2rr-34g9-rvrj ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.