Information Disclosure in Siyuan (CVE-2026-87810)
Summary
Vulnerability in Siyuan (CVE-2026-87810). Risk of unauthorized operations or information disclosure. Exploitable via POST /api/search/fullTextSearchBlock.
Original description
The description as published by the source.
Siyuan before v3.8.2 contains an information disclosure vulnerability in the POST /api/search/fullTextSearchBlock endpoint that filters private blocks from results but returns unfiltered match counts. Unauthenticated publish-mode readers can submit arbitrary search terms to learn whether matching content exists in hidden or unpublished documents and determine the number of matching blocks and pages.
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-2026-87810 has been found in Siyuan.
Attackers can target a specific entry point like POST /api/search/fullTextSearchBlock over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Siyuan CVE-2026-87810" on the vendor's site.
CVE-2026-87810 (Siyuan) — CWE-200 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: POST /api/search/fullTextSearchBlock
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.
Information disclosure (CWE-200) exists in Siyuan. Attackers reach the vulnerable code path via POST /api/search/fullTextSearchBlock without authentication.
Check the vendor advisory for the affected versions of Siyuan. Attack surface: POST /api/search/fullTextSearchBlock.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /api/search/fullTextSearchBlock requests with malformed payloads or SQL meta-characters. Run grep -r 'Siyuan' . 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
-
1Identify exposure identify
grep -r 'Siyuan' . | 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
Siyuanを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /api/search/fullTextSearchBlock' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/search/fullTextSearchBlockへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Post-deployment verification verify
Replay attack against POST /api/search/fullTextSearchBlock on staging to confirm patch closes the vector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 Step 2 と同じログクエリでアラート再発が無いか継続監視。
References
- web github.com
- web vulncheck.com
- web nvd.nist.gov
- web github.com