CVE-2026-29183
CRITICAL NUCLEISiYuan < 3.5.9 - Unauthenticated Reflected Cross-Site Scripting via Dynamic Icon API
Title source: llmExploitation Summary
CVE-2026-29183 has a Nuclei detection template available — see the Nuclei card below for the Shodan/FOFA recon queries.
Description
SiYuan is a personal knowledge management system. Prior to version 3.5.9, an unauthenticated reflected XSS vulnerability exists in the dynamic icon API endpoint "GET /api/icon/getDynamicIcon" when type=8, attacker-controlled content is embedded into SVG output without escaping. Because the endpoint is unauthenticated and returns image/svg+xml, a crafted URL can inject executable SVG/HTML event handlers (for example onerror) and run JavaScript in the SiYuan web origin. This can be chained to perform authenticated API actions and exfiltrate sensitive data when a logged-in user opens the malicious link. This issue has been patched in version 3.5.9.
Nuclei Templates (1)
http.favicon.hash:-1450125239
References (1)
Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N