CVE-2026-86644

LOWPre-NVD 3.53.5—
EchelonGraph scoreHIGH confidence

Score 3.5 from GitHub Security Advisory (severity: LOW) published 2026-09-08. a secondary CVSS source baseline 3.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
3.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 3.5Exploit: Elevated riskExposed: 0

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

A vulnerability was determined in star7th showdoc up to 3.9.1. This vulnerability affects unknown code of the file web_src/public/editor.md/editormd.js of the component API Page Save Endpoint. Executing a manipulation can lead to cross site scripting. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 3.9.2 is able to resolve this issue. This patch is called a8ea1520850b4242f395247f72e87e597506cef0. Upgrading the affected component is recommended. The vendor confirms: "The fix [...] sets Mermaid securityLevel to strict, disables htmlLabels, and sanitizes rendered SVG with DOMPurify."

CVSS v3
3.5
EG Score
3.5(high)
EG Risk
32(Track)
EG Risk 32/100SSVC: 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
Severity35% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
28%
KEV
Not listed

Published

September 8, 2026

Last Modified

September 8, 2026

References (8)

Vendor Advisories for CVE-2026-86644(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 34× 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. 2026-09-25 04:30 UTCEG score recompute
  2. 2026-09-25 04:30 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-23 17:54 UTCEPSS rescore
  5. 2026-09-22 16:01 UTCEPSS rescore
  6. 2026-09-21 21:59 UTCEG score recompute
  7. 2026-09-21 21:59 UTCGHSA enrichment
  8. 2026-09-21 21:09 UTCEPSS rescore
  9. 2026-09-20 20:16 UTCEPSS rescore
  10. 2026-09-18 19:28 UTCEPSS rescore
  11. 2026-09-18 15:28 UTCEG score recompute
  12. 2026-09-18 15:28 UTCGHSA enrichment
  13. 2026-09-17 19:32 UTCEPSS rescore
  14. 2026-09-16 14:09 UTCEPSS rescore
  15. 2026-09-16 05:15 UTCEPSS rescore
  16. 2026-09-15 08:52 UTCEG score recompute
  17. 2026-09-15 08:52 UTCGHSA enrichment
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-15 03:12 UTCEPSS rescore
  20. 2026-09-12 02:21 UTCEG score recompute
  21. 2026-09-12 02:21 UTCGHSA enrichment
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-11 14:53 UTCEPSS rescore
  24. 2026-09-08 19:50 UTCGHSA enrichment
  25. 2026-09-08 16:45 UTCEG score recompute
Show 9 more
  1. 2026-09-08 16:45 UTCGHSA enrichment
  2. 2026-09-08 16:28 UTCNVD updateCVSS v4 → 2
  3. 2026-09-08 15:52 UTCEG score recompute
  4. 2026-09-08 15:52 UTCGHSA enrichment
  5. 2026-09-08 15:49 UTCMITRE cvelistV5CVSS v4 → 5.1
  6. 2026-09-08 14:29 UTCEG score recompute
  7. 2026-09-08 14:26 UTCNVD updateCVSS v4 → 2
  8. 2026-09-08 13:36 UTCEG score recompute
  9. 2026-09-08 13:34 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-86644?
CVE-2026-86644 is a low vulnerability published on September 8, 2026. A vulnerability was determined in star7th showdoc up to 3.9.1. This vulnerability affects unknown code of the file web_src/public/editor.md/editormd.js of the component API Page Save Endpoint. Executing a manipulation can lead to cross site scripting. The attack may be launched remotely. The…
When was CVE-2026-86644 disclosed?
CVE-2026-86644 was first published in the National Vulnerability Database 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-2026-86644 actively exploited?
CVE-2026-86644 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 72.5% of all scored CVEs.
What is the CVSS score of CVE-2026-86644?
CVE-2026-86644 has a CVSS v3 base score of 3.5 (NVD).
How do I remediate CVE-2026-86644?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-86644, 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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