CVE-2026-66010

MEDIUMPre-NVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

Score 6.1 from GitHub Security Advisory published 2026-07-24. The CNA's CVSS baseline 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Elevated
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.1Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowed via CUSTOM_ELEMENT_HANDLING.tagNameCheck, allowing attributes to bypass application security policies. Attackers can preserve sensitive attributes on custom elements that later re-inject them into innerHTML sinks, creating second-order XSS gadgets.

CVSS v3
6.1
EG Score
6.1MEDIUMmedium confidence
EG Risk
43
EG Risk 43/100CISA SSVC

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
Severity61% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
21st
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

July 24, 2026

Last Modified

September 17, 2026

Advisory Details (2)

Auto-updated Jul 24, 2026
🔬 Proof of concept available. Patch available. Sources: github.
githubMentions a patch (unverified)🟡 PoC Available

`CUSTOM_ELEMENT_HANDLING` bypasses `afterSanitizeElements` for allowed custom elements. · Advisory · cure53/DOMPurify · GitHub

https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4
generic

DOMPurify before 3.4.12 Hook Bypass via CUSTOM_ELEMENT_HANDLING | Advisories | VulnCheck

https://www.vulncheck.com/advisories/dompurify-before-hook-bypass-via-custom-element-handling

Vendor Advisories for CVE-2026-66010(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 rangeFix by version rangeDependents
node-dompurify2.4.1+dfsg+~2.4.0-1 ... 3.4.5+dfsg-1 (18 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
node-dompurify3.1.7+dfsg+~3.0.5-2 ... 3.4.5+dfsg-1 (12 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
node-dompurify3.1.7+dfsg+~3.0.5-2 ... 3.4.5+dfsg-1 (8 versions)
  • every version up to 3.4.12+dfsg-1: fixed in 3.4.12+dfsg-1
—
npm(1)
PackageVulnerable rangeFix by version rangeDependents
dompurify—
  • every version up to 3.4.12: fixed in 3.4.12
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 48× 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.

Showing the most recent 100 of 169 total refreshes for this CVE.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-08 17:13 UTCEPSS rescore
  3. 2026-10-07 23:48 UTCEPSS rescore
  4. 2026-10-06 15:18 UTCEPSS rescore
  5. 2026-10-05 17:43 UTCEPSS rescore
  6. 2026-10-04 07:47 UTCEG score recompute
  7. 2026-10-03 14:26 UTCEPSS rescore
  8. 2026-10-03 03:21 UTCEG score recompute
  9. 2026-10-02 17:56 UTCEPSS rescore
  10. 2026-10-01 19:50 UTCEPSS rescore
  11. 2026-10-01 06:12 UTCEG score recompute
  12. 2026-10-01 06:12 UTCGHSA enrichment
  13. 2026-09-30 15:03 UTCEPSS rescore
  14. 2026-09-28 13:51 UTCEPSS rescore
  15. 2026-09-28 05:00 UTCEG score recompute
  16. 2026-09-28 05:00 UTCGHSA enrichment
  17. 2026-09-26 15:59 UTCEPSS rescore
  18. 2026-09-25 10:16 UTCEG score recompute
  19. 2026-09-25 10:16 UTCGHSA enrichment
  20. 2026-09-24 01:05 UTCEG score recompute
  21. 2026-09-24 01:05 UTCGHSA enrichment
  22. 2026-09-23 17:54 UTCEPSS rescore
  23. 2026-09-22 22:37 UTCEG score recompute
  24. 2026-09-22 22:37 UTCGHSA enrichment
  25. 2026-09-20 20:16 UTCEPSS rescore
Show 75 more
  1. 2026-09-20 01:43 UTCEG score recompute
  2. 2026-09-20 01:43 UTCGHSA enrichment
  3. 2026-09-18 22:29 UTCEG score recompute
  4. 2026-09-18 22:29 UTCGHSA enrichment
  5. 2026-09-18 19:28 UTCEPSS rescore
  6. 2026-09-17 18:13 UTCEG score recompute
  7. 2026-09-17 18:13 UTCGHSA enrichment
  8. 2026-09-16 14:08 UTCEPSS rescore
  9. 2026-09-16 11:59 UTCEG score recompute
  10. 2026-09-16 11:59 UTCGHSA enrichment
  11. 2026-09-16 05:15 UTCEPSS rescore
  12. 2026-09-15 09:41 UTCEG score recompute
  13. 2026-09-15 09:41 UTCGHSA enrichment
  14. 2026-09-13 22:19 UTCEG score recompute
  15. 2026-09-13 22:19 UTCGHSA enrichment
  16. 2026-09-12 18:22 UTCEG score recompute
  17. 2026-09-12 18:22 UTCGHSA enrichment
  18. 2026-09-11 16:39 UTCEG score recompute
  19. 2026-09-11 16:39 UTCGHSA enrichment
  20. 2026-09-11 14:53 UTCEPSS rescore
  21. 2026-09-11 09:37 UTCEPSS rescore
  22. 2026-09-10 14:53 UTCEG score recompute
  23. 2026-09-10 14:53 UTCGHSA enrichment
  24. 2026-09-09 08:51 UTCEG score recompute
  25. 2026-09-09 08:51 UTCGHSA enrichment
  26. 2026-09-08 22:01 UTCEPSS rescore
  27. 2026-09-07 21:27 UTCEG score recompute
  28. 2026-09-07 21:27 UTCGHSA enrichment
  29. 2026-09-07 16:01 UTCEPSS rescore
  30. 2026-09-06 13:47 UTCEPSS rescore
  31. 2026-09-05 19:26 UTCEG score recompute
  32. 2026-09-05 19:26 UTCGHSA enrichment
  33. 2026-09-05 15:31 UTCEPSS rescore
  34. 2026-09-04 12:55 UTCEG score recompute
  35. 2026-09-04 12:55 UTCGHSA enrichment
  36. 2026-09-04 05:07 UTCEPSS rescore
  37. 2026-09-02 14:12 UTCEPSS rescore
  38. 2026-09-01 23:18 UTCEG score recompute
  39. 2026-09-01 23:18 UTCGHSA enrichment
  40. 2026-09-01 13:54 UTCEPSS rescore
  41. 2026-09-01 04:40 UTCEPSS rescore
  42. 2026-08-31 01:53 UTCEG score recompute
  43. 2026-08-31 01:53 UTCGHSA enrichment
  44. 2026-08-30 19:17 UTCEPSS rescore
  45. 2026-08-30 01:22 UTCEPSS rescore
  46. 2026-08-30 00:21 UTCEG score recompute
  47. 2026-08-30 00:21 UTCGHSA enrichment
  48. 2026-08-28 21:42 UTCEPSS rescore
  49. 2026-08-27 10:11 UTCEG score recompute
  50. 2026-08-27 10:11 UTCGHSA enrichment
  51. 2026-08-26 14:47 UTCEPSS rescore
  52. 2026-08-26 08:40 UTCEG score recompute
  53. 2026-08-26 08:40 UTCGHSA enrichment
  54. 2026-08-25 13:49 UTCEPSS rescore
  55. 2026-08-25 07:03 UTCEG score recompute
  56. 2026-08-25 07:03 UTCGHSA enrichment
  57. 2026-08-24 05:31 UTCEG score recompute
  58. 2026-08-24 05:31 UTCGHSA enrichment
  59. 2026-08-23 04:00 UTCEG score recompute
  60. 2026-08-23 03:59 UTCGHSA enrichment
  61. 2026-08-23 00:19 UTCEPSS rescore
  62. 2026-08-22 02:28 UTCEG score recompute
  63. 2026-08-22 02:28 UTCGHSA enrichment
  64. 2026-08-21 23:49 UTCEPSS rescore
  65. 2026-08-21 00:56 UTCEG score recompute
  66. 2026-08-21 00:56 UTCGHSA enrichment
  67. 2026-08-20 22:56 UTCEPSS rescore
  68. 2026-08-19 23:25 UTCEG score recompute
  69. 2026-08-19 23:25 UTCGHSA enrichment
  70. 2026-08-19 17:04 UTCEPSS rescore
  71. 2026-08-18 21:54 UTCEG score recompute
  72. 2026-08-18 21:54 UTCGHSA enrichment
  73. 2026-08-18 13:48 UTCEPSS rescore
  74. 2026-08-17 20:22 UTCEG score recompute
  75. 2026-08-17 20:22 UTCGHSA enrichment

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-66010?
CVE-2026-66010 is a medium vulnerability published on July 24, 2026. DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowed via CUSTOMELEMENTHANDLING.tagNameCheck, allowing attributes to bypass application security policies. Attackers can preserve sensitive attributes on custom elements that later re-inject them into…
When was CVE-2026-66010 disclosed?
CVE-2026-66010 was first published on July 24, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66010 actively exploited?
CVE-2026-66010 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (21st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66010?
CVE-2026-66010 has a CVSS base score of 6.1 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-66010?
A fix for CVE-2026-66010 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-66010 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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