SiYuan up to 3.5.4 File Endpoint /api/file/copyFile dest path traversal

CVSS Meta Temp Score
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6.9$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in SiYuan up to 3.5.4. Affected by this issue is some unknown functionality of the file /api/file/copyFile of the component File Endpoint. The manipulation of the argument dest results in path traversal. This vulnerability is known as CVE-2026-25539. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in SiYuan up to 3.5.4. It has been classified as critical. Affected is an unknown function of the file /api/file/copyFile of the component File Endpoint. The manipulation of the argument dest 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, integrity, and availability. CVE summarizes:

SiYuan is a personal knowledge management system. Prior to version 3.5.5, the /api/file/copyFile endpoint does not validate the dest parameter, allowing authenticated users to write files to arbitrary locations on the filesystem. This can lead to Remote Code Execution (RCE) by writing to sensitive locations such as cron jobs, SSH authorized_keys, or shell configuration files. This issue has been patched in version 3.5.5.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-25539 since 02/02/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation requires an enhanced level of successful authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1006.

Upgrading to version 3.5.5 eliminates this vulnerability. Applying the patch d7f790755edf8c78d2b4176171e5a0cdcd720feb 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-2026-5331). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.9

VulDB Base Score: 4.7
VulDB Temp Score: 4.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.2
NVD Vector: 🔒

CNA Base Score: 9.1
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: SiYuan 3.5.5
Patch: d7f790755edf8c78d2b4176171e5a0cdcd720feb

Timelineinfo

02/02/2026 CVE reserved
02/05/2026 +3 days Advisory disclosed
02/05/2026 +0 days VulDB entry created
02/12/2026 +7 days VulDB entry last update

Sourcesinfo

Advisory: GHSA-c4jr-5q7w-f6r9
Status: Confirmed

CVE: CVE-2026-25539 (🔒)
GCVE (CVE): GCVE-0-2026-25539
GCVE (VulDB): GCVE-100-344400
EUVD: 🔒

Entryinfo

Created: 02/05/2026 07:15
Updated: 02/12/2026 08:47
Changes: 02/05/2026 07:15 (68), 02/05/2026 11:28 (1), 02/12/2026 08:47 (11)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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