8.8

CVE-2026-86712: siyuan-note siyuan Cross-site Scripting

CVSS: 8.8v3.1HighDeferred
Published 08-09-2026Last modified 10-09-2026
Open JSON

Vulnerability summary

CVE-2026-86712 is a high (CVSS 8.8) Cross-site Scripting vulnerability in siyuan-note siyuan. EPSS estimates a 0.71% chance of exploitation in the next 30 days, higher than 53.1% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.71%
0%100%
Low · +0.34 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 08-09-2026
    PublishedVulnerability first disclosed.
  2. 10-09-2026
    Last modifiedVulnerability information updated.

Description

SiYuan before 3.8.2 trusts the attacker-writable text/siyuan clipboard MIME type and skips sanitization in the paste handler, allowing code execution in the Node-enabled desktop renderer. Attackers can craft malicious web pages that write to the clipboard, and when pasted into SiYuan, injected scripts execute with full Node.js access through the Electron main process.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.71%

Chance of exploitation in the next 30 days

Percentile

53%

Versus all other CVEs

30-day change

+0.34 pp

From 0.38% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.71%

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

6 links