CVE-2026-100637
SiYuan before v3.8.4 Path Traversal via checkoutRepo sessionID
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
SiYuan before v3.8.4 Path Traversal via checkoutRepo sessionID
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.
- Record
CVE-2026-100637- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L - CVSS 3.1
- 7.6 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L - Weakness
- CWE-73
- Updated
- 2026-11-02
EUVDEUVD-2026-87731
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.
- Record
EUVD-2026-87731- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4fq5-2r2r-5cw9
SiYuan versions before v3.8.4 contain a path traversal vulnerability in the checkoutRepo endpoint...
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.
- Record
GHSA-4fq5-2r2r-5cw9- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.6 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L - Weakness
- CWE-73
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-100637- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.6 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L - Weakness
- CWE-73
- Updated
- 2026-11-02
OSV
SiYuan before v3.8.4 Path Traversal via checkoutRepo sessionID
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.
- Record
CVE-2026-100637- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L - Weakness
- CWE-73
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-100637 is a high vulnerability (CVSS 8.3) in Siyuan-note Siyuan, published September 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.55%, the 46th percentile. No source names a fixed version.
References
github.com/siyuan-note/siyuan/security/advisories/GHSA-jhmh-hr4g-c5g2
vulncheck.com/advisories/siyuan-before-3.8.4-path-traversal-via-checkoutrepo-sessionid
nvd.nist.gov/vuln/detail/CVE-2026-100637