Cross-Site Scripting (XSS) in github.com/siyuan-note/siyuan/kernel (CVE-2026-39846)
Summary
Cross-site scripting in github.com/siyuan-note/siyuan/kernel (CVE-2026-39846). Successful exploitation can lead to full system takeover. Exploitable via nodeIntegration. Mitigation: upgrade to 0.0.0-20260407035653-2f416e5253f1 or later.
Original description
The description as published by the source.
Summary
A malicious note synced to another user can trigger remote code execution in the SiYuan Electron desktop client. The root cause is that table caption content is stored without safe escaping and later unescaped into rendered HTML, creating a stored XSS sink. Because the desktop renderer runs with nodeIntegration enabled and contextIsolation disabled, attacker-controlled JavaScript executes with access to Node.js APIs. In practice, an attacker can import a crafted note into a synced workspace, wait for the victim to sync, and achieve code execution when the victim opens the note.
Details
The vulnerability exists in the table caption handling path. When a table block is parsed, the caption attribute is saved into the node's IAL properties without proper HTML escaping. Later, during rendering, that value is read back, passed through HTML unescaping, and written directly into the output DOM. This turns an attacker-controlled caption into active HTML inside the rendered note.
I confirmed that a crafted table caption containing encoded HTML such as <img src=x onerror=...> is rendered as a live DOM element instead of inert text. This makes the issue a stored XSS. I also confirmed that the most practical delivery path is not Markdown import, but a crafted .sy.zip note imported into a synced workspace. Once synced to another desktop client, opening the note executes the payload automatically.
In the Electron desktop client, this XSS results in code ex…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-39846 has been found in github.com/siyuan-note/siyuan/kernel.
Attackers can target a specific entry point like nodeIntegration over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.0/10.
What to do: upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260407035653-2f416e5253f1 or later.
If unsure, ask your IT team or search "github.com/siyuan-note/siyuan/kernel CVE-2026-39846" on the vendor's site.
CVE-2026-39846 (github.com/siyuan-note/siyuan/kernel) — CWE-79 / CVSS v3 9.0
Attack vector: remote (network-reachable)
Attack surface: nodeIntegration / contextIsolation / caption
Patched: 0.0.0-20260407035653-2f416e5253f1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in github.com/siyuan-note/siyuan/kernel. Attackers reach the vulnerable code path via nodeIntegration.
Check the vendor advisory for the affected versions of github.com/siyuan-note/siyuan/kernel. Attack surface: nodeIntegration / contextIsolation / caption.
Severity: Critical (CVSS 9.0/10). Successful exploitation can lead to full system takeover.
Update to 0.0.0-20260407035653-2f416e5253f1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/siyuan-note/siyuan/kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'github.com/siyuan-note/siyuan/kernel' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/siyuan-note/siyuan/kernelを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260407035653-2f416e5253f1ステージング環境で 0.0.0-20260407035653-2f416e5253f1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com