CVE-2026-87808

MEDIUMPre-NVD 4.94.9—
EchelonGraph scoreHIGH confidence

Score 4.9 from GitHub Security Advisory (severity: HIGH) published 2026-09-09. a secondary CVSS source baseline 4.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
4.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.9Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
4.9
EG Score
4.9(high)
EG Risk
38(Track)
EG Risk 38/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity49% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
26%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Sep 9, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
generic

SiYuan before v3.8.2 Read-Only Boundary Bypass via fullTextSearchBlock | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-before-3.8.2-read-only-boundary-bypass-via-fulltextsearchblock
github_commit

commit d5e2d0bce0df (siyuan-note/siyuan)

Fix landed in siyuan-note/siyuan commit d5e2d0bce0df — awaiting tagged release

https://github.com/siyuan-note/siyuan/commit/d5e2d0bce0dffef5f61bd8066954bc2d41181fc5
github Patch Available🟡 PoC Available

Incomplete fix for CVE-2026-32767 / GHSA-j7wh-x834-p3r7: `/api/search/fullTextSearchBlock` still bypasses the read-only boundary · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-4qwm-3p58-vh67

Vendor Advisories for CVE-2026-87808(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 19× in last 7d / 32× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 14:43 UTCEG score recompute
  2. 2026-09-19 14:43 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 12:47 UTCEG score recompute
  5. 2026-09-18 12:47 UTCGHSA enrichment
  6. 2026-09-17 19:32 UTCEPSS rescore
  7. 2026-09-17 10:51 UTCEG score recompute
  8. 2026-09-17 10:51 UTCGHSA enrichment
  9. 2026-09-16 14:09 UTCEPSS rescore
  10. 2026-09-16 08:54 UTCEG score recompute
  11. 2026-09-16 08:54 UTCGHSA enrichment
  12. 2026-09-16 05:15 UTCEPSS rescore
  13. 2026-09-15 06:29 UTCEG score recompute
  14. 2026-09-15 06:29 UTCGHSA enrichment
  15. 2026-09-15 03:12 UTCEPSS rescore
  16. 2026-09-14 04:33 UTCEG score recompute
  17. 2026-09-14 04:33 UTCGHSA enrichment
  18. 2026-09-13 02:37 UTCEG score recompute
  19. 2026-09-13 02:37 UTCGHSA enrichment
  20. 2026-09-12 00:40 UTCEG score recompute
  21. 2026-09-12 00:40 UTCGHSA enrichment
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-11 14:53 UTCEPSS rescore
  24. 2026-09-10 22:43 UTCGHSA enrichment
  25. 2026-09-09 20:45 UTCGHSA enrichment
Show 7 more
  1. 2026-09-09 15:29 UTCEG score recompute
  2. 2026-09-09 15:29 UTCGHSA enrichment
  3. 2026-09-09 14:20 UTCEG score recompute
  4. 2026-09-09 14:20 UTCGHSA enrichment
  5. 2026-09-09 12:25 UTCEG score recompute
  6. 2026-09-09 11:30 UTCEG score recompute
  7. 2026-09-09 11:29 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-87808?
CVE-2026-87808 is a medium vulnerability published on September 9, 2026. 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:…
When was CVE-2026-87808 disclosed?
CVE-2026-87808 was first published in the National Vulnerability Database on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87808 actively exploited?
CVE-2026-87808 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 74.3% of all scored CVEs.
What is the CVSS score of CVE-2026-87808?
CVE-2026-87808 has a CVSS v3 base score of 4.9 (NVD).
How do I remediate CVE-2026-87808?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-87808, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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