Vulnerability-Lookup

CVE-2026-83606 (GCVE-0-2026-83606)

Vulnerability from cvelistv5 – Published: 2026-09-01 14:21 – Updated: 2026-09-01 14:57

Title

xmldom PI grammar regex ReDoS: quadratic backtracking on unterminated processing instructions

Summary

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0-beta.9 until 0.9.11, the processing-instruction production in lib/grammar.js lets the greedy S+ separator and lazy Char*? data group repeatedly repartition a long whitespace tail when the required closing ?> is absent. Both parsePI and parseProcessingInstruction apply the expression to the entire remaining source, causing quadratic backtracking during DOMParser.parseFromString() under default options and allowing a small unauthenticated XML input to stall the Node.js event loop. This issue is fixed in @xmldom/xmldom version 0.9.11.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-01 14:57 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption
CWE-1333 - Inefficient Regular Expression Complexity

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/xmldom/xmldom/security/advisor…	x_refsource_CONFIRM
https://github.com/xmldom/xmldom/pull/1039	x_refsource_MISC
https://github.com/xmldom/xmldom/commit/73df6b8bd…	x_refsource_MISC
https://github.com/xmldom/xmldom/releases/tag/0.9.11	x_refsource_MISC

Impacted products

2 products

Vendor	Product	Version	CPE status
xmldom	xmldom	Affected: >= 0.9.0-beta.9, < 0.9.11	guessed
@xmldom	xmldom	Affected: >= 0.9.0-beta.9, < 0.9.11	guessed

Show details on NVD website

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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CVE-2026-83606 (GCVE-0-2026-83606)

Tags

Sightings

Nomenclature