CVE-2026-100637: External Control of File Name or Path in siyuan-note siyuan
SiYuan versions before v3.8.4 contain a path traversal vulnerability in the checkoutRepo endpoint that allows authenticated administrators to write JSON files outside the workspace. Attackers can supply a sessionID parameter containing directory traversal sequences to overwrite arbitrary JSON files in pre-existing kernel-writable directories outside workspace boundaries.
AI Analysis
Technical Summary
CVE-2026-100637 describes a path traversal vulnerability in SiYuan note-taking software versions prior to 3.8.4. The vulnerability exists in the checkoutRepo endpoint, where authenticated administrators can manipulate the sessionID parameter to include directory traversal sequences. This enables writing JSON files outside the workspace, potentially overwriting arbitrary files in kernel-writable directories outside the workspace boundaries.
Potential Impact
An attacker with administrator privileges can overwrite arbitrary JSON files outside the workspace, which may lead to unauthorized modification of configuration or data files. This could affect system integrity or application behavior. The CVSS 4.0 score of 8.3 (high severity) reflects the network attack vector, low attack complexity, no user interaction, and high impact on integrity and availability.
Mitigation Recommendations
A fix is available in SiYuan version 3.8.4. Users should upgrade to version 3.8.4 or later to remediate this vulnerability. No other mitigation steps are indicated.
CVE-2026-100637: External Control of File Name or Path in siyuan-note siyuan
Description
SiYuan versions before v3.8.4 contain a path traversal vulnerability in the checkoutRepo endpoint that allows authenticated administrators to write JSON files outside the workspace. Attackers can supply a sessionID parameter containing directory traversal sequences to overwrite arbitrary JSON files in pre-existing kernel-writable directories outside workspace boundaries.
CVSS v4.0
Score 8.3high
Affected software
siyuan-note
siyuan
pkg:github/siyuan-note/siyuanRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-100637 describes a path traversal vulnerability in SiYuan note-taking software versions prior to 3.8.4. The vulnerability exists in the checkoutRepo endpoint, where authenticated administrators can manipulate the sessionID parameter to include directory traversal sequences. This enables writing JSON files outside the workspace, potentially overwriting arbitrary files in kernel-writable directories outside the workspace boundaries.
Potential Impact
An attacker with administrator privileges can overwrite arbitrary JSON files outside the workspace, which may lead to unauthorized modification of configuration or data files. This could affect system integrity or application behavior. The CVSS 4.0 score of 8.3 (high severity) reflects the network attack vector, low attack complexity, no user interaction, and high impact on integrity and availability.
Mitigation Recommendations
A fix is available in SiYuan version 3.8.4. Users should upgrade to version 3.8.4 or later to remediate this vulnerability. No other mitigation steps are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-26T02:32:35.658Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ab7c9a5f7a7c5410652fd21
Added to database: 09/26/2026, 13:33:25 UTC
Last enriched: 09/26/2026, 14:04:05 UTC
Last updated: 09/27/2026, 01:57:11 UTC
Views: 12
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