CVE-2026-87815

HIGHPre-NVD 8.78.7—
EchelonGraph scoreHIGH confidence

Score 8.7 from GitHub Security Advisory (severity: HIGH) published 2026-09-09. a secondary CVSS source baseline 8.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: Elevated riskExposed: 0

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

SiYuan versions before v3.8.2 contain a path traversal vulnerability in the /api/riff/removeRiffDeck endpoint that fails to validate the deckID parameter. An authenticated administrator can supply path traversal sequences to delete arbitrary .deck and .cards files outside the workspace directory.

CVSS v3
8.7
EG Score
8.7(high)
EG Risk
55(Track)
EG Risk 55/100SSVC: 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
Severity87% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 14, 2026

Advisory Details (2)

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

SiYuan before v3.8.2 Path Traversal via removeRiffDeck | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-before-3.8.2-path-traversal-via-removeriffdeck
github Patch Available🟡 PoC Available

Path traversal in /api/riff/removeRiffDeck allows admin to delete arbitrary .deck/.cards files outside the workspace · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-94vh-rpgr-rpwc

Vendor Advisories for CVE-2026-87815(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 30× in last 7d / 45× 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 20:07 UTCEG score recompute
  2. 2026-09-19 20:07 UTCGHSA enrichment
  3. 2026-09-19 08:43 UTCGHSA enrichment
  4. 2026-09-18 21:20 UTCEG score recompute
  5. 2026-09-18 21:20 UTCGHSA enrichment
  6. 2026-09-18 19:28 UTCEPSS rescore
  7. 2026-09-18 09:36 UTCGHSA enrichment
  8. 2026-09-17 22:13 UTCEG score recompute
  9. 2026-09-17 22:13 UTCGHSA enrichment
  10. 2026-09-17 19:32 UTCEPSS rescore
  11. 2026-09-17 10:50 UTCGHSA enrichment
  12. 2026-09-16 23:27 UTCEG score recompute
  13. 2026-09-16 23:27 UTCGHSA enrichment
  14. 2026-09-16 14:09 UTCEPSS rescore
  15. 2026-09-16 12:04 UTCEG score recompute
  16. 2026-09-16 12:04 UTCGHSA enrichment
  17. 2026-09-16 05:15 UTCEPSS rescore
  18. 2026-09-16 00:41 UTCGHSA enrichment
  19. 2026-09-15 13:17 UTCEG score recompute
  20. 2026-09-15 13:17 UTCGHSA enrichment
  21. 2026-09-15 03:12 UTCEPSS rescore
  22. 2026-09-15 01:54 UTCGHSA enrichment
  23. 2026-09-14 14:31 UTCEG score recompute
  24. 2026-09-14 14:31 UTCGHSA enrichment
  25. 2026-09-14 13:36 UTCEG score recompute
Show 20 more
  1. 2026-09-14 13:36 UTCGHSA enrichment
  2. 2026-09-14 03:12 UTCEG score recompute
  3. 2026-09-14 03:12 UTCGHSA enrichment
  4. 2026-09-13 15:49 UTCGHSA enrichment
  5. 2026-09-13 04:26 UTCGHSA enrichment
  6. 2026-09-12 17:02 UTCEG score recompute
  7. 2026-09-12 17:02 UTCGHSA enrichment
  8. 2026-09-12 05:39 UTCGHSA enrichment
  9. 2026-09-11 18:16 UTCEG score recompute
  10. 2026-09-11 18:16 UTCGHSA enrichment
  11. 2026-09-11 14:53 UTCEPSS rescore
  12. 2026-09-11 14:53 UTCEPSS rescore
  13. 2026-09-11 06:53 UTCGHSA enrichment
  14. 2026-09-10 19:30 UTCGHSA enrichment
  15. 2026-09-10 08:07 UTCGHSA enrichment
  16. 2026-09-09 20:44 UTCEG score recompute
  17. 2026-09-09 20:44 UTCGHSA enrichment
  18. 2026-09-09 12:25 UTCEG score recompute
  19. 2026-09-09 11:30 UTCEG score recompute
  20. 2026-09-09 11:29 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-87815?
CVE-2026-87815 is a high vulnerability published on September 9, 2026. SiYuan versions before v3.8.2 contain a path traversal vulnerability in the /api/riff/removeRiffDeck endpoint that fails to validate the deckID parameter. An authenticated administrator can supply path traversal sequences to delete arbitrary .deck and .cards files outside the workspace directory.
When was CVE-2026-87815 disclosed?
CVE-2026-87815 was first published in the National Vulnerability Database on September 9, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87815 actively exploited?
CVE-2026-87815 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 80.9% of all scored CVEs.
What is the CVSS score of CVE-2026-87815?
CVE-2026-87815 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-87815?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-87815, 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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