Remote code execution via cross-origin snippet injection
Published Mar 31, 2026 · Updated Mar 31, 2026
Cross-origin policy bypass in SiYuan before 3.6.2 allows remote attackers to execute code by submitting a JavaScript snippet. The CORS middleware in kernel/server/serve.go grants arbitrary origins private-network access to /api/snippet/setSnippet, which stores attacker-controlled JavaScript for Electron to load. A user need only visit a malicious website while the desktop app is running; the saved snippet then runs with Node.js access and the user's operating-system privileges.
Summary
What happened
Cross-origin policy bypass in SiYuan before 3.6.2 allows remote attackers to execute code by submitting a JavaScript snippet. The CORS middleware in kernel/server/serve.go grants arbitrary origins private-network access to /api/snippet/setSnippet, which stores attacker-controlled JavaScript for Electron to load. A user need only visit a malicious website while the desktop app is running; the saved snippet then runs with Node.js access and the user's operating-system privileges.
The record
- CVE
- CVE-2026-34449
- Published
- Mar 31, 2026
- Updated
- Mar 31, 2026
- Vendor
- SiYuan Note
- Product
- SiYuan
- Classifications
- CWE-942, T1189, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 31, 2026CVE publishedPublication date reported by the CVE source.
- Mar 31, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.6.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-68p4-j234-43mv malicious webpage proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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