CVE-2026-74902

Code execution via filename HTML injection

Published Aug 18, 2026 · Updated Aug 18, 2026

Cross-site scripting in SiYuan before 3.7.4 allows attackers to execute OS commands via a crafted filename during drag, drop, or paste. The validateFile() logic in app/src/protyle/upload/index.ts concatenates file.name into status and error HTML and passes it to showMessage(), which renders it with insertAdjacentHTML without escaping. Reachability requires the victim to drag, drop, or paste an attacker-controlled file into the desktop editor; in Electron builds with nodeIntegration enabled, the injected script can invoke child_process with the user's privileges.

CVSS severity9.3
Critical
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cross-site scripting in SiYuan before 3.7.4 allows attackers to execute OS commands via a crafted filename during drag, drop, or paste. The validateFile() logic in app/src/protyle/upload/index.ts concatenates file.name into status and error HTML and passes it to showMessage(), which renders it with insertAdjacentHTML without escaping. Reachability requires the victim to drag, drop, or paste an attacker-controlled file into the desktop editor; in Electron builds with nodeIntegration enabled, the injected script can invoke child_process with the user's privileges.

The record

CVE
CVE-2026-74902
Published
Aug 18, 2026
Updated
Aug 18, 2026
Vendor
SiYuan Note
Product
SiYuan
Classifications
CWE-79, CWE-94, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

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

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <3.7.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

SiYuan Note · SiYuanversion=0 <3.7.4

Published CVSS scores

9.3VulnCheck CNACVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
8.6VulnCheck CNACVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-94Improper Control of Generation of Code ('Code Injection')
T1203Exploitation for Client Execution

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo