SiYuan Vulnerable to Arbitrary File Read via File Copy Functionality

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N · score source

EPSS

• CVE-2026-23851: 0.52% estimated exploitation activity in the next 30 days; percentile 44.08 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The SiYuan Note application (v3.5.3) contains a logic vulnerability in the /api/file/globalCopyFiles endpoint. The function allows authenticated users to copy files from any location on the server's filesystem into the application's workspace without proper path validation Details The vulnerability exists in the api/file.go source code. The function globalCopyFiles accepts a list of source paths (srcs) from the JSON request body. While the code checks if the source file exists using filelock.IsExist(src), it fails to validate whether the source path resides within the authorized workspace directory. PoC The following steps demonstrate how to exfiltrate the /etc/passwd file. 1. The attacker sends a request to copy the system file /etc/passwd to the root of the application workspace (/). <img width="1537" height="357" alt="image" src="https://github.com/user-attachments/assets/7c8e5fe8-f609-4263-8685-eedf3cf22400" / 2. The attacker downloads the copied file using the standard…

Published by the source

21 Jan 2026, 01:01 UTC

Last modified by the source

21 Jan 2026, 01:01 UTC

Source last checked

26 Oct 2026, 15:14 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-94c7-g2fj-7682

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# Patch Next advisory brief: CVE-2026-23851

Advisory: SiYuan Vulnerable to Arbitrary File Read via File Copy Functionality
IDs: CVE-2026-23851, GHSA-94c7-g2fj-7682
Record: https://patchnext.com/advisories/cve-2026-23851 (revision 1, source checked 26 Oct 2026, 15:14 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/siyuan-note/siyuan/kernel 0.0.0-20260118092521-f8f4b517077b. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/siyuan-note/siyuan/kernel: affected < 0.0.0-20260118092521-f8f4b517077b; fixed in 0.0.0-20260118092521-f8f4b517077b

## Suggested inspection (read-only)
- Go github.com/siyuan-note/siyuan/kernel: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/siyuan-note/siyuan/kernel.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-94c7-g2fj-7682 (GitHub-reviewed advisory GHSA-94c7-g2fj-7682 lists affected ranges: Go github.com/siyuan-note/siyuan/kernel >=0 <0.0.0-20260118092521-f8f4b517077b)

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