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.

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.

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.

Affected products

Siyuan-note Siyuan

Weakness classification (CWE)

CWE-73 — External Control of File Name or Path

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (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.