CVE-2026-100636

HIGHPre-NVD 7.67.6—
EchelonGraph scoreHIGH confidence

Score 7.6 from GitHub Security Advisory (severity: HIGH) published 2026-09-26. A secondary CVSS source baseline 7.6; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
7.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.6Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

SiYuan versions before v3.8.4 contain a path traversal vulnerability in the exportBrowserHTML endpoint that allows authenticated administrators to write arbitrary HTML content to index.html outside the workspace directory. Attackers can supply a folder parameter with directory traversal sequences to escape the export directory and overwrite index.html in any pre-existing kernel-writable location, enabling stored XSS or workspace defacement.

CVSS v3
7.6
EG Score
7.6HIGHhigh confidence
EG Risk
50
EG Risk 50/100CISA 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
Severity76% × 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
0.5%
EPSS %ILE
43rd
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

September 26, 2026

Last Modified

September 28, 2026

Advisory Details (2)

Auto-updated Sep 26, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

SiYuan before v3.8.4 Path Traversal via exportBrowserHTML folder | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-before-3.8.4-path-traversal-via-exportbrowserhtml-folder
github Patch Available🟡 PoC Available

Admin path traversal in exportBrowserHTML via folder allows out-of-workspace arbitrary-content index.html write · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-jf98-m24w-gm9m

Vendor Advisories for CVE-2026-100636(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 28× in last 7d / 35× 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. 2026-10-04 23:21 UTCEPSS rescore
  2. 2026-10-04 16:35 UTCGHSA enrichment
  3. 2026-10-04 03:40 UTCGHSA enrichment
  4. 2026-10-03 14:46 UTCEG score recompute
  5. 2026-10-03 14:46 UTCGHSA enrichment
  6. 2026-10-03 14:25 UTCEPSS rescore
  7. 2026-10-03 01:51 UTCEG score recompute
  8. 2026-10-03 01:51 UTCGHSA enrichment
  9. 2026-10-02 12:56 UTCGHSA enrichment
  10. 2026-10-02 00:02 UTCEG score recompute
  11. 2026-10-02 00:02 UTCGHSA enrichment
  12. 2026-10-01 19:49 UTCEPSS rescore
  13. 2026-10-01 10:28 UTCGHSA enrichment
  14. 2026-09-30 21:34 UTCEG score recompute
  15. 2026-09-30 21:34 UTCGHSA enrichment
  16. 2026-09-30 15:02 UTCEPSS rescore
  17. 2026-09-30 08:34 UTCGHSA enrichment
  18. 2026-09-29 19:40 UTCEG score recompute
  19. 2026-09-29 19:39 UTCGHSA enrichment
  20. 2026-09-29 15:20 UTCEPSS rescore
  21. 2026-09-29 06:38 UTCEG score recompute
  22. 2026-09-29 06:38 UTCGHSA enrichment
  23. 2026-09-28 17:43 UTCEG score recompute
  24. 2026-09-28 17:42 UTCGHSA enrichment
  25. 2026-09-28 17:03 UTCEG score recompute
Show 10 more
  1. 2026-09-28 17:03 UTCGHSA enrichment
  2. 2026-09-28 13:50 UTCEPSS rescore
  3. 2026-09-28 05:22 UTCGHSA enrichment
  4. 2026-09-27 16:27 UTCEG score recompute
  5. 2026-09-27 16:27 UTCGHSA enrichment
  6. 2026-09-27 03:34 UTCEG score recompute
  7. 2026-09-27 03:33 UTCGHSA enrichment
  8. 2026-09-26 14:34 UTCEG score recompute
  9. 2026-09-26 13:39 UTCEG score recompute
  10. 2026-09-26 13:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-100636?
CVE-2026-100636 is a high vulnerability published on September 26, 2026. SiYuan versions before v3.8.4 contain a path traversal vulnerability in the exportBrowserHTML endpoint that allows authenticated administrators to write arbitrary HTML content to index.html outside the workspace directory. Attackers can supply a folder parameter with directory traversal sequences…
When was CVE-2026-100636 disclosed?
CVE-2026-100636 was first published on September 26, 2026, with the most recent update on September 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-100636 actively exploited?
CVE-2026-100636 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-100636?
CVE-2026-100636 has a CVSS base score of 7.6 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-100636?
A fix for CVE-2026-100636 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100636 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-100636

Explore →

Is Your Infrastructure Affected by CVE-2026-100636?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs