8.7

CVE-2026-87815: siyuan-note siyuan External Control of File Name or Path

CVSS: 8.7v3.1HighDeferred
Published 09-09-2026Last modified 14-09-2026
Open JSON

Vulnerability summary

CVE-2026-87815 is a high (CVSS 8.7) External Control of File Name or Path vulnerability in siyuan-note siyuan. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.3% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v3.1 (CVE.org)
EPSS score
0.48%
0%100%
Low · +0.21 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 09-09-2026
    PublishedVulnerability first disclosed.
  2. 14-09-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.48%

Chance of exploitation in the next 30 days

Percentile

40%

Versus all other CVEs

30-day change

+0.21 pp

From 0.27% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.48%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Siyuan-note1 product

1 vendor · 1 product

References

2 links