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.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-73"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100637.json"
}{
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "3.8.4"
},
{
"fixed": "v3.8.4"
}
],
"source": [
"AFFECTED_FIELD",
"DESCRIPTION"
]
}