SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-variant paths like PublishAccess.json to disclose sensitive publish-access configuration and metadata.
{
"cwe_ids": [
"CWE-22"
],
"cna_assigner": "VulnCheck",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85580.json"
}{
"source": [
"AFFECTED_FIELD",
"DESCRIPTION"
],
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "3.8.2"
},
{
"fixed": "v3.8.2"
}
]
}