7.4

CVE-2026-87812: siyuan-note siyuan Cross-site Scripting

CVSS: 7.4v4.0HighDeferred
Published 09-09-2026Last modified 10-09-2026
Open JSON

Vulnerability summary

CVE-2026-87812 is a high (CVSS 7.4) Cross-site Scripting vulnerability in siyuan-note siyuan. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.7% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.4/10
010
High · v4.0 (CVE.org)
EPSS score
0.36%
0%100%
Low · +0.16 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. 10-09-2026
    Last modifiedVulnerability information updated.

Description

SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in Bazaar package cards where the iconURL metadata is inserted directly into HTML img src attributes without escaping. Attackers can inject malicious URLs with event handlers that execute JavaScript in the authenticated SiYuan origin when users view Bazaar listings, enabling API requests and application state manipulation.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.36%

Chance of exploitation in the next 30 days

Percentile

29%

Versus all other CVEs

30-day change

+0.16 pp

From 0.20% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.36%

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