CVE-2026-34605
SiYuan vulnerable to reflected XSS via SVG namespace prefix bypass in SanitizeSVG (getDynamicIcon, unauthenticated)
Impact
SiYuan is a personal knowledge management system. From version 3.6.0 to before version 3.6.2, the SanitizeSVG function introduced in version 3.6.0 to fix XSS in the unauthenticated /api/icon/getDynamicIcon endpoint can be bypassed by using namespace-prefixed element names such as <x:script xmlns:x="http://www.w3.org/2000/svg">. The Go HTML5 parser records the element's tag as "x:script" rather than "script", so the tag check passes it through. The SVG is served with Content-Type: image/svg+xml and no Content Security Policy; when a browser opens the response directly, its XML parser resolves the prefix to the SVG namespace and executes the embedded script. This issue has been patched in version 3.6.2.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/siyuan-note/siyuan/kernel | < 0.0.0-20260330031106-f09953afc57a | 0.0.0-20260330031106-f09953afc57a |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| B3log | Siyuan | from 3.6.0 before 3.6.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-73g7-86qr-jrg3
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-73g7-86qr-jrg3
- https://github.com/siyuan-note/siyuan/issues/17246
- https://github.com/siyuan-note/siyuan/releases/tag/v3.6.2
- https://nvd.nist.gov/vuln/detail/CVE-2026-34605