CVE-2026-45375: SiYuan Bazaar marketplace renders unescaped package `name` and `version` metadata, allowing stored XSS and Electron code execution

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.4%, percentile 34: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 34% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes github.com/siyuan-note/siyuan/kernel (Go) <= 0.0.0-20260421031503-96dfe0bea474, no fixed version listed. Check your lockfile, including transitive dependencies.

What it is

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, SiYuan's Bazaar (community marketplace) renders the name and version fields of a package's plugin.json (and the equivalent theme.json / template.json / widget.json / icon.json) into the Settings → Marketplace UI without HTML escaping. The kernel-side helper sanitizePackageDisplayStrings in kernel/bazaar/package.go HTML-escapes only Author, DisplayName, and Description — Name and Version flow through to the renderer raw. The frontend at app/src/config/bazaar.ts substitutes them into HTML template strings via ${item.preferredName} / ${data.name} / v${data.version} and assigns the result to innerHTML. As a consequence, malicious HTML in either field is parsed and executed when a user opens the marketplace tab. This vulnerability is fixed in 3.7.0.

From the GitHub advisory

Summary

SiYuan's Bazaar (community marketplace) renders the name and version fields of a package's plugin.json (and the equivalent theme.json / template.json / widget.json / icon.json) into the Settings → Marketplace UI without HTML escaping. The kernel-side helper sanitizePackageDisplayStrings in kernel/bazaar/package.go HTML-escapes only Author, DisplayName, and Description — Name and Version flow through to the renderer raw. The frontend at app/src/config/bazaar.ts substitutes them into HTML template strings via ${item.preferredName} / ${data.name} / v${data.version} and assigns the result to innerHTML. As a consequence, malicious HTML in either field is parsed and executed when a user opens the marketplace tab.

Because the desktop client is built on Electron with nodeIntegration: true, contextIsolation: false, and webSecurity: false (app/electron/main.js:407-411), the resulting cross-site scripting executes in a renderer with full access to Node.js APIs, escalating directly to arbitrary OS command execution under the victim's account. The trigger is zero-click on the list view — opening Settings → Marketplace → Downloaded → Plugins is sufficient; no Install/Update click is required.

A second preferredName path exists: when displayName: {} (empty locale map), GetPreferredLocaleString falls back to the unescaped pkg.Name, so even a normal-looking visible plugin name carries the payload through the same sink.

Details

Weakness type: CWE-79, CWE-116.

Product: github.com/siyuan-note/siyuan/kernel (Go) · Assigned by: GitHub_M · Published: 2026-05-14

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: required (a user must click/open something)
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.41% probability of exploitation activity in the next 30 days; percentile 34.

Timeline

• 2026-05-13 — GitHub-reviewed advisory GHSA-27qc-m5gf-jv5r published (critical)
• 2026-05-14 — CVE record published by GitHub_M
• 2026-05-16 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-27qc-m5gf-jv5r github.com
2. CVE.org record CVE-2026-45375 cve.org
3. NVD entry CVE-2026-45375 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com

Critical Go advisories · Today’s Security Digest