SiYuan versions before v3.8.4 contain a path traversal vulnerability in the exportBrowserHTML endpoint that allows authenticated administrators to write arbitrary HTML content to index.html outside the workspace directory. Attackers can supply a folder parameter with directory traversal sequences to escape the export directory and overwrite index.html in any pre-existing kernel-writable location, enabling stored XSS or workspace defacement.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-22"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100636.json"
}{
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "3.8.4"
},
{
"fixed": "v3.8.4"
}
],
"source": [
"AFFECTED_FIELD",
"DESCRIPTION"
]
}