CVE-2026-31809 Details.
SiYuan <= v3.5.9 - Cross Site Scripting
Atlas does not check this one. Needs requests that change data.
To test for this one, the check would have to send requests that could change data on the site. Atlas only ever reads public pages, so it does not run this check.
About CVE-2026-31809. What It Means.
SiYuan v3.5.10 contains a reflected XSS caused by improper sanitization of javascript: href attributes allowing ASCII control characters to bypass prefix checks in SVG sanitizer, letting unauthenticated attackers execute JavaScript via /api/icon/getDynamicIcon.
Affected Product. What Is Hit.
- Vendor
- siyuan-note
- Product
- SiYuan Note SiYuan
References. Where To Read More.
More CVEs In SiYuan Note SiYuan.
- CVE-2026-54069HighInformation onlySiYuan Note <= 3.6.5 - Authentication BypassSiYuan NoteCVSS9.1
- CVE-2026-33476HighInformation onlySiYuan <= v3.6.1 - Path TraversalSiYuan NoteCVSS7.5
- CVE-2026-54066HighSiYuan <= 3.6.5 - Unauthenticated Path TraversalSiYuan NoteCVSS7.5
- CVE-2026-34453HighInformation onlySiYuan <= v3.6.1 - Bookmark Data DisclosureSiYuan NoteCVSS7.5
- CVE-2026-29183MediumInformation onlySiYuan Note - Cross-Site ScriptingSiYuan NoteCVSS6.1
- CVE-2026-34605MediumInformation onlySiYuan Note - Cross-Site ScriptingSiYuan NoteCVSS6.1
FAQ
Common Questions.
SiYuan <= v3.5.9 - Cross Site Scripting. SiYuan v3.5.10 contains a reflected XSS caused by improper sanitization of javascript: href attributes allowing ASCII control characters to bypass prefix checks in SVG sanitizer, letting unauthenticated attackers execute JavaScript via /api/icon/getDynamicIcon.
No. To test for this one, the check would have to send requests that could change data on the site. Atlas only ever reads public pages, so it does not run this check. The facts about CVE-2026-31809 are on this page, and you can request a demo to see how Brandefense watches your whole external attack surface.
CVE-2026-31809 is not on the CISA Known Exploited Vulnerabilities list at the time of writing, but it is still worth fixing.
Update SiYuan Note SiYuan to the latest version from the vendor, or follow the vendor's advice to switch off the affected feature. Vendor links are listed on this page when they are known.
This page lists the public facts about CVE-2026-31809. Atlas does not run a check for it, so nothing here says whether a particular site is affected.