# CVE-2026-87808

## Summary

- **CVE ID:** CVE-2026-87808
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-693
- **Published:** Sep 9, 2026
- **Last Modified:** Sep 9, 2026

## Description

SiYuan versions <= 3.8.1 contain an incomplete fix for CVE-2026-32767 (GHSA-j7wh-x834-p3r7). The prior fix (commit d5e2d0bc) added an administrator check for SQL mode (method=2) in POST /api/search/fullTextSearchBlock, but the endpoint still does not enforce the application's read-only boundary: for method=2 it forwards caller-supplied SQL to the blocks database query path without calling model.CheckReadonly or CheckReadonlyStatementInBox. As a result, when a workspace runs in read-only mode (--readonly=true), an authenticated administrator can submit arbitrary SQL through /api/search/fullTextSearchBlock and obtain raw read access to the blocks database, even though the dedicated /api/query/sql endpoint is blocked in that mode. Fixed in v3.8.2.

## Affected Products

- siyuan-note — siyuan (0)
- siyuan-note — siyuan (3.8.2)

## References

- [CNA](https://github.com/siyuan-note/siyuan/security/advisories/GHSA-4qwm-3p58-vh67)
- [CNA](https://github.com/siyuan-note/siyuan/commit/d5e2d0bce0dffef5f61bd8066954bc2d41181fc5)
- [CNA](https://www.vulncheck.com/advisories/siyuan-before-3.8.2-read-only-boundary-bypass-via-fulltextsearchblock)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.32%
- **EPSS Percentile:** 25.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._