How severe is GHSA-73g7-86qr-jrg3?

GHSA-73g7-86qr-jrg3 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-73g7-86qr-jrg3?

GHSA-73g7-86qr-jrg3 affects the following packages: github.com/siyuan-note/siyuan/kernel (Go). Ecosystems affected: Go.

How do I fix GHSA-73g7-86qr-jrg3?

Update github.com/siyuan-note/siyuan/kernel to 0.0.0-20260330031106-f09953afc57a or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-73g7-86qr-jrg3 is resolved across your whole dependency graph.

How do I detect GHSA-73g7-86qr-jrg3 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siyuan-note/siyuan/kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-73g7-86qr-jrg3 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-73g7-86qr-jrg3?

O3 pinpoints whether GHSA-73g7-86qr-jrg3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-73g7-86qr-jrg3 actively exploited in the wild?

No public exploit code has been indexed for GHSA-73g7-86qr-jrg3 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-73g7-86qr-jrg3?

GHSA-73g7-86qr-jrg3 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 37th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-73g7-86qr-jrg3?

GHSA-73g7-86qr-jrg3 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for GHSA-73g7-86qr-jrg3?

A Nuclei detection template exists for GHSA-73g7-86qr-jrg3, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was GHSA-73g7-86qr-jrg3 published, and has it been updated?

GHSA-73g7-86qr-jrg3 was published on April 1, 2026 and was last updated on April 6, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

GHSA-73g7-86qr-jrg3

MEDIUM

SiYuan vulnerable to reflected XSS via SVG namespace prefix bypass in SanitizeSVG (getDynamicIcon, unauthenticated)

Also known asCVE-2026-34605

Published

Apr 1, 2026

Updated

Apr 6, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk37th percentile+0.33%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐹github.com/siyuan-note/siyuan/kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The SanitizeSVG function introduced in v3.6.0 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.

Details

The getDynamicIcon route is registered without authentication:

// kernel/server/serve.go
ginServer.Handle("GET", "/api/icon/getDynamicIcon", getDynamicIcon)

For type 8, the content query parameter is inserted directly into an SVG <text> element using fmt.Sprintf with no HTML encoding:

// kernel/api/icon.go:579-584
return fmt.Sprintf(`
    <svg id="dynamic_icon_type8" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512">
        <path d="..."/>
        <text x="50%%" y="55%%" ...>%s</text>
    </svg>`, ..., content)

SanitizeSVG then parses the SVG with github.com/88250/lute/html and removes elements whose lowercased tag name matches a fixed list:

// kernel/util/misc.go:249-252
tag := strings.ToLower(c.Data)
if tag == "script" || tag == "iframe" || tag == "object" || tag == "embed" ||
    tag == "foreignobject" || "animate" == tag || ... {
    n.RemoveChild(c)

The lute HTML parser stores the full qualified name including any namespace prefix in Node.Data. A payload like <x:script xmlns:x="http://www.w3.org/2000/svg"> gets Data = "x:script". The check tag == "script" is false, so the element is not removed and survives in the rendered output.

Confirmed with the same library version used by SiYuan:

html.Parse input:  <x:script xmlns:x="http://www.w3.org/2000/svg">alert(1)</x:script>
Node.Data result:  "x:script"   (not "script")
Removed by check:  false
Rendered output:   <x:script xmlns:x="http://www.w3.org/2000/svg">alert(1)</x:script>

The same bypass works for every element on the blocklist: x:iframe, x:object, x:foreignObject, etc.

The fix is to strip the namespace prefix before comparing:

localName := tag
if i := strings.LastIndex(tag, ":"); i >= 0 {
    localName = tag[i+1:]
}
if localName == "script" || localName == "iframe" || ...

PoC

GET /api/icon/getDynamicIcon?type=8&color=red&content=%3C%2Ftext%3E%3Cx%3Ascript%20xmlns%3Ax%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%3Ealert%28document.domain%29%3C%2Fx%3Ascript%3E%3Ctext%3E HTTP/1.1
Host: 127.0.0.1:6806

Decoded content value:

</text><x:script xmlns:x="http://www.w3.org/2000/svg">alert(document.domain)</x:script><text>

The response is a valid SVG with the script element intact. Opening the URL directly in a browser triggers the alert, confirming script execution at the SiYuan server origin.

Impact

Any user whose SiYuan instance is reachable over a local network is exposed. An attacker on the same network can craft the URL and share it. When the victim opens it in a browser, JavaScript executes at the http://<siyuan-host>:6806 origin. Because SiYuan sets Access-Control-Allow-Origin: * and the script runs same-origin, it can call any API endpoint using the victim's existing session cookies, including endpoints to read all notes, export data, or modify settings. No authentication or prior access is needed to construct the payload.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/siyuan-note/siyuan/kernel`	all versions	0.0.0-20260330031106-f09953afc57a

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siyuan-note/siyuan/kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/siyuan-note/siyuan/kernel to 0.0.0-20260330031106-f09953afc57a or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-73g7-86qr-jrg3 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-73g7-86qr-jrg3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-73g7-86qr-jrg3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary The `SanitizeSVG` function introduced in v3.6.0 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. ### Detail

O3 Security · Impact-Aware SCA

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