SiYuan up to 3.5.3 globalCopyFiles path traversal

HistoryDiffrelatejsonxmlCTI

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical has been found in SiYuan up to 3.5.3. The impacted element is an unknown function of the file /api/file/globalCopyFiles. Performing a manipulation results in path traversal. This vulnerability is known as CVE-2026-23851. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in SiYuan up to 3.5.3. This affects some unknown processing of the file /api/file/globalCopyFiles. The manipulation with an unknown input leads to a path traversal vulnerability. CWE is classifying the issue as CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. This is going to have an impact on confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-23851 since 01/16/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1006 for this issue.

Upgrading to version 3.5.4 eliminates this vulnerability. Applying the patch b2274baba2e11c8cf8901b0c5c871e5b27f1f6dd is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-3291). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

SiYuan

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Path traversal
CWE: CWE-22
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: SiYuan 3.5.4
Patch: b2274baba2e11c8cf8901b0c5c871e5b27f1f6dd

Timelineinfo

01/16/2026 CVE reserved
01/19/2026 +3 days VulDB entry created
01/20/2026 +0 days Advisory disclosed
01/31/2026 +11 days VulDB entry last update

Sourcesinfo

Advisory: 16860
Status: Confirmed

CVE: CVE-2026-23851 (🔒)
GCVE (CVE): GCVE-0-2026-23851
GCVE (VulDB): GCVE-100-341865
EUVD: 🔒

Entryinfo

Created: 01/20/2026 00:08
Updated: 01/31/2026 05:14
Changes: 01/20/2026 00:08 (69), 01/20/2026 03:34 (1), 01/31/2026 05:14 (11)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.