# CVE-2026-87815

## Summary

- **CVE ID:** CVE-2026-87815
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H)
- **CWE:** CWE-73
- **Published:** Sep 9, 2026
- **Last Modified:** Sep 9, 2026

## Description

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.

## Affected Products

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

## References

- [CNA](https://github.com/siyuan-note/siyuan/security/advisories/GHSA-94vh-rpgr-rpwc)
- [CNA](https://www.vulncheck.com/advisories/siyuan-before-3.8.2-path-traversal-via-removeriffdeck)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.27%
- **EPSS Percentile:** 18.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-12._