CVE-2026-85580

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-04. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.5Exploit: Elevated riskExposed: 0

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

SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-variant paths like PublishAccess.json to disclose sensitive publish-access configuration and metadata.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
45%
KEV
Not listed

Published

September 4, 2026

Last Modified

September 8, 2026

Advisory Details (2)

Auto-updated Sep 4, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

SiYuan before v3.8.2 Path Guard Bypass via Case Mismatch | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-before-3.8.2-path-guard-bypass-via-case-mismatch
github Patch Available🟡 PoC Available

Linux MCP publish-access path guard bypass exposes publishAccess.json · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mmgw-3mx9-cfwp

Vendor Advisories for CVE-2026-85580(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 20× in last 7d / 65× 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 03:12 UTCEG score recompute
  2. 2026-09-25 03:12 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-24 04:09 UTCEG score recompute
  5. 2026-09-24 04:09 UTCGHSA enrichment
  6. 2026-09-23 17:54 UTCEPSS rescore
  7. 2026-09-23 05:16 UTCEG score recompute
  8. 2026-09-23 05:16 UTCGHSA enrichment
  9. 2026-09-22 16:01 UTCEPSS rescore
  10. 2026-09-22 06:22 UTCEG score recompute
  11. 2026-09-22 06:22 UTCGHSA enrichment
  12. 2026-09-21 21:09 UTCEPSS rescore
  13. 2026-09-21 07:29 UTCEG score recompute
  14. 2026-09-21 07:29 UTCGHSA enrichment
  15. 2026-09-20 20:16 UTCEPSS rescore
  16. 2026-09-20 08:09 UTCEG score recompute
  17. 2026-09-20 08:09 UTCGHSA enrichment
  18. 2026-09-19 08:43 UTCEG score recompute
  19. 2026-09-19 08:43 UTCGHSA enrichment
  20. 2026-09-18 19:28 UTCEPSS rescore
  21. 2026-09-18 09:42 UTCEG score recompute
  22. 2026-09-18 09:42 UTCGHSA enrichment
  23. 2026-09-17 19:32 UTCEPSS rescore
  24. 2026-09-17 10:49 UTCEG score recompute
  25. 2026-09-17 10:49 UTCGHSA enrichment
Show 40 more
  1. 2026-09-16 14:09 UTCEPSS rescore
  2. 2026-09-16 11:51 UTCEG score recompute
  3. 2026-09-16 11:51 UTCGHSA enrichment
  4. 2026-09-16 05:15 UTCEPSS rescore
  5. 2026-09-15 12:58 UTCEG score recompute
  6. 2026-09-15 12:58 UTCGHSA enrichment
  7. 2026-09-15 03:12 UTCEPSS rescore
  8. 2026-09-15 03:12 UTCEPSS rescore
  9. 2026-09-14 14:05 UTCEG score recompute
  10. 2026-09-14 14:05 UTCGHSA enrichment
  11. 2026-09-13 15:12 UTCGHSA enrichment
  12. 2026-09-12 16:19 UTCEG score recompute
  13. 2026-09-12 16:19 UTCGHSA enrichment
  14. 2026-09-11 17:26 UTCEG score recompute
  15. 2026-09-11 17:26 UTCGHSA enrichment
  16. 2026-09-11 14:53 UTCEPSS rescore
  17. 2026-09-11 14:53 UTCEPSS rescore
  18. 2026-09-10 18:05 UTCEG score recompute
  19. 2026-09-10 18:05 UTCGHSA enrichment
  20. 2026-09-09 19:12 UTCEG score recompute
  21. 2026-09-09 19:12 UTCGHSA enrichment
  22. 2026-09-08 22:01 UTCEPSS rescore
  23. 2026-09-08 20:19 UTCGHSA enrichment
  24. 2026-09-08 11:00 UTCEG score recompute
  25. 2026-09-08 11:00 UTCGHSA enrichment
  26. 2026-09-07 12:06 UTCEG score recompute
  27. 2026-09-07 12:06 UTCGHSA enrichment
  28. 2026-09-06 13:48 UTCEPSS rescore
  29. 2026-09-06 13:12 UTCEG score recompute
  30. 2026-09-06 13:12 UTCGHSA enrichment
  31. 2026-09-05 15:31 UTCEPSS rescore
  32. 2026-09-05 14:19 UTCEG score recompute
  33. 2026-09-05 14:19 UTCGHSA enrichment
  34. 2026-09-04 15:26 UTCEG score recompute
  35. 2026-09-04 15:26 UTCGHSA enrichment
  36. 2026-09-04 14:26 UTCEG score recompute
  37. 2026-09-04 14:25 UTCGHSA enrichment
  38. 2026-09-04 12:22 UTCEG score recompute
  39. 2026-09-04 11:34 UTCEG score recompute
  40. 2026-09-04 11:33 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-85580?
CVE-2026-85580 is a medium vulnerability published on September 4, 2026. SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-variant paths like PublishAccess.json to disclose sensitive…
When was CVE-2026-85580 disclosed?
CVE-2026-85580 was first published in the National Vulnerability Database on September 4, 2026, with the most recent update 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-2026-85580 actively exploited?
CVE-2026-85580 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 54.8% of all scored CVEs.
What is the CVSS score of CVE-2026-85580?
CVE-2026-85580 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-85580?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-85580, 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

Explore the affected products and dependency analysis for CVE-2026-85580

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