Cyber Resilience

CVE-2026-50551

Critical

Published: 24 June 2026

Published
24 June 2026
Modified
25 June 2026
KEV Added
Patch
CVSS Score v3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0044 35.3th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-50551 is a critical-severity Cross-site Scripting (CWE-79) vulnerability. Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 35.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, SiYuan contains a stored cross-site scripting (XSS) vulnerability in the Attribute View (database) asset cell renderer that escalates to remote code execution (RCE) in the Electron desktop client. This…

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vulnerability is fixed in 3.7.0.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
Why these techniques?

Stored XSS directly enables client-side code execution that escalates to RCE in Electron (T1203); the payload is JavaScript executed in the desktop client context (T1059.007).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References