CVE-2026-54759
Published: 24 June 2026
Summary
CVE-2026-54759 is a high-severity Cross-site Scripting (CWE-79) vulnerability. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 17.6th 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
- 🇪🇺 ENISA EUVD: EUVD-2026-39101
Vulnerability details
SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, Lute's HTML sanitizer does not remove <iframe> elements. Combined with the SiYuan Electron client's permissive security configuration, an attacker can include a malicious <iframe> in a Bazaar package README…
more
that executes arbitrary commands on the victim's machine when the package details are viewed. No package installation is required. This vulnerability is fixed in 3.7.0.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
XSS via unsanitized iframe in Electron client directly enables client-side code execution (arbitrary commands) without user interaction beyond viewing content.
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.
Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.
Validates web inputs to reject script-related content that could produce XSS.
Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.