CVE-2026-23851 SiYuan Vulnerable to Arbitrary File Read via File Copy Functionality
Authenticated attackers can read arbitrary files from the server filesystem via the globalCopyFiles API due to missing path validation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-23851?
CVE-2026-23851 is a high-severity path traversal vulnerability in B3log Siyuan, published on 19 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
SiYuan is a personal knowledge management system. Versions prior to 3.5.4 contain 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. 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. Version 3.5.4 patches the issue.
Weakness: CWE-22
Which versions are affected by CVE-2026-23851?
3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260118092521-f8f4b517077b |
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260118092521-f8f4b517077b |
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260118092521-f8f4b517077b |
Products include B3log Siyuan.
How do I fix CVE-2026-23851?
Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260118092521-f8f4b517077b or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-23851 being exploited?
There is no known exploitation of CVE-2026-23851 in the wild and no public exploit code.
Other vulnerabilities in B3log Siyuan
- CVE-2026-32938 SiYuan has an Arbitrary File Read in its Desktop Publish Service
- CVE-2026-33669 SiYuan has Arbitrary Document Reading within the Publishing Service
- CVE-2026-33670 SiYuan has directory traversal within its publishing service
- CVE-2026-32767 SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API
- CVE-2024-53504 SQL injection in n/a
Sources
Also known as GHSA-94c7-g2fj-7682, GO-2026-4346.