Vulnerability in Siyuan-Note Siyuan
CVE-2026-87815
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-94vh-rpgr-rpwc (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-3.8.2-path-traversal-via-removeriffd… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-87815?
- CVE-2026-87815 is a high-severity vulnerability in Siyuan-Note Siyuan, classified under External Control of File Name or Path. CVSS score: 8.7/10. Published 2026-09-09.
- How severe is CVE-2026-87815?
- High severity. CVSS v3 base score is 8.7 out of 10.