Siyuan has an Unauthenticated Arbitrary File Read via Path Traversal

Exploitation

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

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-33476: 3.26% estimated exploitation activity in the next 30 days; percentile 88.37 (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 kernel exposes an unauthenticated file-serving endpoint under /appearance/filepath. Due to improper path sanitization, attackers can perform directory traversal and read arbitrary files accessible to the server process. Authentication checks explicitly exclude this endpoint, allowing exploitation without valid credentials. Details Vulnerable Code Location File: kernel/server/serve.go Technical Root Cause The handler constructs a filesystem path by joining a base directory (appearancePath) with user-controlled URL segments. Key issues: 1. Unsanitized User Input The path component extracted from the request is not validated or normalized to prevent traversal. This preserves sequences such as: 2. Unsafe Path Joining filepath.Join() does not enforce directory confinement. This escapes the intended directory. 3. Direct File Serving The resolved path is served without verification: Authentication Bypass (Unauthenticated Access) Authentication middleware explicitly skips…

Published by the source

20 Mar 2026, 20:43 UTC

Last modified by the source

25 Mar 2026, 18:22 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hhgj-gg9h-rjp7

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# Patch Next advisory brief: CVE-2026-33476

Advisory: Siyuan has an Unauthenticated Arbitrary File Read via Path Traversal
IDs: CVE-2026-33476, GHSA-hhgj-gg9h-rjp7
Record: https://patchnext.com/advisories/cve-2026-33476 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/siyuan-note/siyuan/kernel: affected <= 0.0.0-20260317012524-fe4523fff2c8

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## 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-hhgj-gg9h-rjp7 (GitHub-reviewed advisory GHSA-hhgj-gg9h-rjp7 lists affected ranges: Go github.com/siyuan-note/siyuan/kernel >=0 <=0.0.0-20260317012524-fe4523fff2c8)

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