CVE-2026-85580Public exploitNetwork attack vectorHinoki check available

Publish-access metadata disclosure via case-mismatched path

Published Sep 4, 2026 · Updated Sep 4, 2026

Path traversal in the MCP file-access handler in SiYuan before 3.8.2 allows remote authenticated users to read publish-access metadata. On Linux, the guard compares the protected publishAccess.json basename case-sensitively, so a case-variant request resolves to the protected file but evades rejection. Access requires a low-privilege MCP caller, and the disclosed data is limited to publication visibility, configuration, and password-related metadata.

CVSS severity7.1
High
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Path traversal in the MCP file-access handler in SiYuan before 3.8.2 allows remote authenticated users to read publish-access metadata. On Linux, the guard compares the protected publishAccess.json basename case-sensitively, so a case-variant request resolves to the protected file but evades rejection. Access requires a low-privilege MCP caller, and the disclosed data is limited to publication visibility, configuration, and password-related metadata.

The record

CVE
CVE-2026-85580
Published
Sep 4, 2026
Updated
Sep 4, 2026
Vendor
SiYuan Note
Product
SiYuan
Classifications
CWE-22, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.8.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

SiYuan Note · SiYuanversion=0 <3.8.2

Published CVSS scores

6.5VulnCheck CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
7.1VulnCheck CNACVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

Public exploit references

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Technologies

Your stack

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Your stack

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