CVE-2026-100637

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 week
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: None knownExposed services: Not assessed

A fix is available — apply it.

SiYuan versions before v3.8.4 contain a path traversal vulnerability in the checkoutRepo endpoint that allows authenticated administrators to write JSON files outside the workspace. Attackers can supply a sessionID parameter containing directory traversal sequences to overwrite arbitrary JSON files in pre-existing kernel-writable directories outside workspace boundaries.

CVSS v3
7.6
EG Score
7.6HIGHhigh confidence
EG Risk
39
EG Risk 39/100CISA 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%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
38th
KEV
Not listed

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

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). 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 26, 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 checkoutRepo sessionID | Advisories | VulnCheck

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

Admin path traversal in checkoutRepo via sessionID allows out-of-workspace JSON file write · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-jhmh-hr4g-c5g2

Vendor Advisories for CVE-2026-100637(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 27× in last 7d / 32× 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 15:02 UTCGHSA enrichment
  2. 2026-10-04 02:13 UTCEG score recompute
  3. 2026-10-04 02:13 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-03 13:25 UTCGHSA enrichment
  6. 2026-10-03 00:36 UTCEG score recompute
  7. 2026-10-03 00:36 UTCGHSA enrichment
  8. 2026-10-02 11:46 UTCGHSA enrichment
  9. 2026-10-01 22:55 UTCEG score recompute
  10. 2026-10-01 22:55 UTCGHSA enrichment
  11. 2026-10-01 19:49 UTCEPSS rescore
  12. 2026-10-01 10:06 UTCGHSA enrichment
  13. 2026-09-30 21:18 UTCEG score recompute
  14. 2026-09-30 21:18 UTCGHSA enrichment
  15. 2026-09-30 15:02 UTCEPSS rescore
  16. 2026-09-30 08:29 UTCGHSA enrichment
  17. 2026-09-29 19:40 UTCEG score recompute
  18. 2026-09-29 19:39 UTCGHSA enrichment
  19. 2026-09-29 15:20 UTCEPSS rescore
  20. 2026-09-29 06:46 UTCEG score recompute
  21. 2026-09-29 06:46 UTCGHSA enrichment
  22. 2026-09-28 17:58 UTCEG score recompute
  23. 2026-09-28 17:58 UTCGHSA enrichment
  24. 2026-09-28 13:50 UTCEPSS rescore
  25. 2026-09-28 05:01 UTCGHSA enrichment
Show 7 more
  1. 2026-09-27 16:13 UTCEG score recompute
  2. 2026-09-27 16:12 UTCGHSA enrichment
  3. 2026-09-27 03:24 UTCEG score recompute
  4. 2026-09-27 03:23 UTCGHSA enrichment
  5. 2026-09-26 14:34 UTCEG score recompute
  6. 2026-09-26 13:40 UTCEG score recompute
  7. 2026-09-26 13:30 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-100637?
CVE-2026-100637 is a high vulnerability published on September 26, 2026. SiYuan versions before v3.8.4 contain a path traversal vulnerability in the checkoutRepo endpoint that allows authenticated administrators to write JSON files outside the workspace. Attackers can supply a sessionID parameter containing directory traversal sequences to overwrite arbitrary JSON files…
When was CVE-2026-100637 disclosed?
CVE-2026-100637 was first published on September 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-100637 actively exploited?
CVE-2026-100637 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (38th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-100637?
CVE-2026-100637 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-2026-100637?
A fix for CVE-2026-100637 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100637 are linked in the Vendor Advisories panel on this page.

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