CVE-2026-93923Network attack vectorHinoki check available

Stored XSS via unescaped heading style attributes

Published Sep 18, 2026 · Updated Sep 18, 2026

Stored cross-site scripting in SiYuan 3.8.4 and earlier allows remote attackers to execute code through crafted heading styles. Outline and bookmark dock renderers place unescaped heading style attributes into generated HTML, allowing stored values to create executable markup. Reachability requires a crafted notebook or access to an administrative write endpoint; Electron execution gains the application user's system privileges.

CVSS severityUnavailable
Unscored
EPSS probability0.60%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored cross-site scripting in SiYuan 3.8.4 and earlier allows remote attackers to execute code through crafted heading styles. Outline and bookmark dock renderers place unescaped heading style attributes into generated HTML, allowing stored values to create executable markup. Reachability requires a crafted notebook or access to an administrative write endpoint; Electron execution gains the application user's system privileges.

The record

CVE
CVE-2026-93923
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
SiYuan Note
Product
SiYuan
Classifications
CWE-79, T1204.002
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=3.8.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

SiYuan Note · SiYuanversion=0 <=3.8.4

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.002User Execution: Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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