CVE-2026-45553: NiceGUI: Local file disclosure via Docutils file insertion in ui.restructured_text()

May 18, 2026 (updated June 9, 2026)

ui.restructured_text() renders reStructuredText server-side with Docutils without disabling file insertion directives.

When a NiceGUI application passes attacker-controlled content to ui.restructured_text(), an attacker can use standard Docutils directives (include, csv-table with :file:, raw with :file:) to read local files readable by the NiceGUI server process.

Applications that only pass trusted static strings to ui.restructured_text() are not affected.

References

github.com/advisories/GHSA-jfrm-rx66-g536
github.com/zauberzeug/nicegui/releases/tag/v3.12.0
github.com/zauberzeug/nicegui/security/advisories/GHSA-jfrm-rx66-g536
nvd.nist.gov/vuln/detail/CVE-2026-45553

Code Behaviors & Features

Detect and mitigate CVE-2026-45553 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →