CVE-2026-63670

MEDIUMPre-NVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% 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
Elevated
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: Elevated riskExposed: 0

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

ApostropheCMS is an open-source Node.js content management system. Prior to 2.17.6, sanitizeHtml() can pass disallowed executable markup through packages/sanitize-html/index.js when textarea or xmp is included in allowedTags because a literal solidus after the raw-text end-tag name is treated as text by htmlparser2 and the ontext handler emits that content without escaping, while a browser parses the following img onerror markup as active HTML. This issue is fixed in version 2.17.6.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: 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
Severity61% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

August 17, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Aug 17, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit.
github_commit

commit eae1fb2b72ec (apostrophecms/apostrophe)

Fix landed in apostrophecms/apostrophe commit eae1fb2b72ec — awaiting tagged release

https://github.com/apostrophecms/apostrophe/commit/eae1fb2b72ec5d1c27d0977509c6482a0408f725
github_pr

fix for </textarea/> vulnerability

Fix merged in apostrophecms/apostrophe PR #5501 on 2026-07-08 — awaiting tagged release

https://github.com/apostrophecms/apostrophe/pull/5501
github Patch Available🟡 PoC Available

Mutation-XSS / allowedTags bypass via literal `</textarea/>` solidus close · Advisory · apostrophecms/apostrophe · GitHub

https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-jxwj-j7wr-gfrw

Vendor Advisories for CVE-2026-63670(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
sanitize-html—2.17.6—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× 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.

  1. 2026-09-19 02:33 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 02:10 UTCEG score recompute
  4. 2026-09-17 01:47 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-16 01:24 UTCEG score recompute
  8. 2026-09-14 00:31 UTCEG score recompute
  9. 2026-09-13 00:08 UTCEG score recompute
  10. 2026-09-11 23:45 UTCEG score recompute
  11. 2026-09-11 14:53 UTCEPSS rescore
  12. 2026-09-11 09:37 UTCEPSS rescore
  13. 2026-09-10 21:54 UTCEG score recompute
  14. 2026-09-09 03:38 UTCEG score recompute
  15. 2026-09-08 22:01 UTCEPSS rescore
  16. 2026-09-07 16:01 UTCEPSS rescore
  17. 2026-09-07 10:32 UTCEG score recompute
  18. 2026-09-06 13:47 UTCEPSS rescore
  19. 2026-09-06 09:03 UTCEG score recompute
  20. 2026-09-05 15:31 UTCEPSS rescore
  21. 2026-09-05 08:39 UTCEG score recompute
  22. 2026-09-04 08:16 UTCEG score recompute
  23. 2026-09-04 05:07 UTCEPSS rescore
  24. 2026-09-03 07:46 UTCEG score recompute
  25. 2026-09-02 14:12 UTCEPSS rescore
Show 31 more
  1. 2026-09-02 07:18 UTCEG score recompute
  2. 2026-09-01 13:54 UTCEPSS rescore
  3. 2026-09-01 06:54 UTCEG score recompute
  4. 2026-09-01 04:40 UTCEPSS rescore
  5. 2026-08-31 06:20 UTCEG score recompute
  6. 2026-08-30 19:17 UTCEPSS rescore
  7. 2026-08-30 05:53 UTCEG score recompute
  8. 2026-08-30 01:22 UTCEPSS rescore
  9. 2026-08-29 05:29 UTCEG score recompute
  10. 2026-08-28 21:42 UTCEPSS rescore
  11. 2026-08-27 21:53 UTCEG score recompute
  12. 2026-08-27 14:25 UTCEPSS rescore
  13. 2026-08-26 21:30 UTCEG score recompute
  14. 2026-08-26 14:46 UTCEPSS rescore
  15. 2026-08-25 21:07 UTCEG score recompute
  16. 2026-08-25 13:49 UTCEPSS rescore
  17. 2026-08-24 20:44 UTCEG score recompute
  18. 2026-08-23 20:21 UTCEG score recompute
  19. 2026-08-23 00:19 UTCEPSS rescore
  20. 2026-08-22 19:58 UTCEG score recompute
  21. 2026-08-21 23:49 UTCEPSS rescore
  22. 2026-08-21 19:35 UTCEG score recompute
  23. 2026-08-20 22:55 UTCEPSS rescore
  24. 2026-08-19 18:49 UTCEG score recompute
  25. 2026-08-19 17:04 UTCEPSS rescore
  26. 2026-08-18 18:25 UTCEG score recompute
  27. 2026-08-18 18:15 UTCEG score recompute
  28. 2026-08-18 13:48 UTCEPSS rescore
  29. 2026-08-17 20:29 UTCEG score recompute
  30. 2026-08-17 20:02 UTCEG score recompute
  31. 2026-08-17 19:59 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-63670?
CVE-2026-63670 is a medium vulnerability published on August 17, 2026. ApostropheCMS is an open-source Node.js content management system. Prior to 2.17.6, sanitizeHtml() can pass disallowed executable markup through packages/sanitize-html/index.js when textarea or xmp is included in allowedTags because a literal solidus after the raw-text end-tag name is treated as…
When was CVE-2026-63670 disclosed?
CVE-2026-63670 was first published in the National Vulnerability Database on August 17, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63670 actively exploited?
CVE-2026-63670 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 78.3% of all scored CVEs.
What is the CVSS score of CVE-2026-63670?
CVE-2026-63670 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-63670?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63670, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63670

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