CVE-2026-83609

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 74% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0 until 0.9.12, the shared reg() builder in lib/grammar.js compiles the anchored QName_exact validator with the multiline flag, so ^ and $ validate only one line instead of the complete name. createElementNS, createAttributeNS, createDocumentType, and createAttribute consequently accept a malformed XML name whose first line is valid and whose later text injects markup when serialized through either the default path or requireWellFormed: true. The triggering ECMAScript line terminators are U+000A, U+000D, U+2028, and U+2029. This issue is fixed in @xmldom/xmldom version 0.9.12.

CVSS v3
8.7
EG Score
8.7(medium)
EG Risk
54(Track)
EG Risk 54/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity87% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
26%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 8, 2026

Advisory Details (4)

Auto-updated Sep 1, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available

Release 0.9.12 (xmldom/xmldom)

Patch available: xmldom/xmldom 0.9.12

https://github.com/xmldom/xmldom/releases/tag/0.9.12
github_commit Patch Available

commit 7b2ec67e1750 (xmldom/xmldom)

Patch available: xmldom/xmldom 0.9.12 (contains commit 7b2ec67e1750)

https://github.com/xmldom/xmldom/commit/7b2ec67e1750daadd0bb06c92e875e726544a362
github_pr Patch Available

Security release 0.9.12 — parser/DOM DoS, serializer name checks, multiline-anchor bypass

Patch available: xmldom/xmldom 0.9.12 (PR #1071 merged 2026-08-21)

https://github.com/xmldom/xmldom/pull/1071
github Patch Available🟡 PoC Available

Creation-time XML Name/QName validation is bypassable via an embedded line terminator, allowing injection on the default serialization path · Advisory · xmldom/xmldom · GitHub

https://github.com/xmldom/xmldom/security/advisories/GHSA-3px3-54cx-rmw9

Vendor Advisories for CVE-2026-83609(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
node-xmldom0.8.6-1 ... 0.9.9-1 (10 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
node-xmldom0.9.10-1 ... 0.9.9-1 (8 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
node-xmldom0.9.10-1 ... 0.9.9-1 (7 versions)0.9.12-1—
npm(1)
PackageVulnerable rangeFixed inDependents
@xmldom/xmldom—0.9.12—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 13× in last 7d / 33× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 22:00 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 20:49 UTCEG score recompute
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-16 19:38 UTCEG score recompute
  6. 2026-09-16 14:09 UTCEPSS rescore
  7. 2026-09-16 06:58 UTCEG score recompute
  8. 2026-09-16 05:15 UTCEPSS rescore
  9. 2026-09-15 05:36 UTCEG score recompute
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-15 03:12 UTCEPSS rescore
  12. 2026-09-14 04:24 UTCEG score recompute
  13. 2026-09-13 03:14 UTCEG score recompute
  14. 2026-09-12 02:02 UTCEG score recompute
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-11 14:53 UTCEPSS rescore
  17. 2026-09-11 13:26 UTCEG score recompute
  18. 2026-09-10 12:14 UTCEG score recompute
  19. 2026-09-09 09:48 UTCEG score recompute
  20. 2026-09-08 22:01 UTCEPSS rescore
  21. 2026-09-08 03:30 UTCEG score recompute
  22. 2026-09-07 01:56 UTCEG score recompute
  23. 2026-09-06 13:48 UTCEPSS rescore
  24. 2026-09-04 23:27 UTCEG score recompute
  25. 2026-09-04 10:47 UTCEG score recompute
Show 8 more
  1. 2026-09-04 05:07 UTCEPSS rescore
  2. 2026-09-02 20:42 UTCEG score recompute
  3. 2026-09-02 14:12 UTCEPSS rescore
  4. 2026-09-01 19:30 UTCEG score recompute
  5. 2026-09-01 18:25 UTCEG score recompute
  6. 2026-09-01 15:40 UTCEG score recompute
  7. 2026-09-01 14:34 UTCEG score recompute
  8. 2026-09-01 14:33 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-83609?
CVE-2026-83609 is a high vulnerability published on September 1, 2026. xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0 until 0.9.12, the shared reg() builder in lib/grammar.js compiles the anchored QName_exact validator with the multiline flag, so ^ and $ validate only one line instead of the…
When was CVE-2026-83609 disclosed?
CVE-2026-83609 was first published in the National Vulnerability Database on September 1, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-83609 actively exploited?
CVE-2026-83609 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 74.1% of all scored CVEs.
What is the CVSS score of CVE-2026-83609?
CVE-2026-83609 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-83609?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-83609, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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