CVE-2026-83605 xmldom CVE debrief

Who should care

Developers and administrators using @xmldom/xmldom in their applications, especially those handling XML parsing and serialization, should be aware of this vulnerability and take necessary actions to patch or mitigate it. This includes identifying and inventorying all systems using affected versions of @xmldom/xmldom, applying patches or updates to versions 0.8.14 or 0.9.11 of @xmldom/xmldom, and monitoring for suspicious activity related to XML parsing and serialization. Additionally, implementing compensating controls, such as input validation and sanitization, can help mitigate the vulnerability. Affected systems should be identified and patched with versions 0.8.14 or 0.9.11 of @xmldom/xmldom as soon as possible. The vulnerability has a HIGH CVSS score of 8.7, indicating a high-priority defensive response is required. Evidence from the NVD and CVE Program records indicates a vulnerability in @xmldom/xmldom versions prior to 0.8.14 and 0.9.11, and xmldom version 0.6.0 and earlier. The vulnerability allows for attribute name validation bypass, enabling injection of additional attributes, including event handlers, into browser-consumed output. Synthesized xmlns:PREFIX declarations expose the same unchecked-name boundary. This issue is fixed in @xmldom/xmldom versions 0.8.14 and 0.9.11; no fixed version is available for xmldom. The CVE record was published on 2026-09-01T15:17:38.317Z and has not been modified since then. The NVD entry is currently 8.7 HIGH. The xmldom module, a pure JavaScript W3C standard-based DOMParser and XMLSerializer, has a vulnerability in versions prior to 0.8.14 and 0.9.11, and xmldom version 0.6.0 and earlier. The vulnerability occurs due to a bypass in attribute name validation, allowing for injection of additional attributes, including event handlers, into browser-consumed output. XMLSerializer.serializeToString() emits attribute names verbatim, and requireWellFormed: true did not validate them, so a crafted name can terminate the intended attribute and inject additional attributes, including event handlers, into browser-consumed output. Element.setAttribute() calls the private _createAttribute(name) path without validating the name,

Technical summary

The xmldom module, a pure JavaScript W3C standard-based DOMParser and XMLSerializer, has a vulnerability in versions prior to 0.8.14 and 0.9.11, and xmldom version 0.6.0 and earlier. The vulnerability occurs due to a bypass in attribute name validation, allowing for injection of additional attributes, including event handlers, into browser-consumed output. This issue is fixed in @xmldom/xmldom versions 0.8.14 and 0.9.11; no fixed version is available for xmldom. The vulnerability allows for attribute name validation bypass, enabling injection of additional attributes, including event handlers, into browser-consumed output.

Defensive priority

High-priority defensive actions are required due to the HIGH CVSS score of 8.7. Affected systems should be identified and patched with versions 0.8.14 or 0.9.11 of @xmldom/xmldom as soon as possible.

Recommended defensive actions

• Identify and inventory all systems using affected versions of @xmldom/xmldom
• Apply patches or updates to versions 0.8.14 or 0.9.11 of @xmldom/xmldom
• Monitor for suspicious activity related to XML parsing and serialization
• Implement compensating controls, such as input validation and sanitization
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

Evidence from the NVD and CVE Program records indicates a vulnerability in @xmldom/xmldom versions prior to 0.8.14 and 0.9.11, and xmldom version 0.6.0 and earlier. The vulnerability allows for attribute name validation bypass, enabling injection of additional attributes, including event handlers.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.