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Medium · 6.9 CVE-2026-33332 EUVD-2026-20086GHSA-w5g8-5849-vj76PYSEC-2026-2233

NiceGUI's unvalidated chunk size parameter in media routes can cause memory exhaustion

Published Mar 24, 2026 · Updated Mar 25, 2026 · Assigned by GitHub_M

Description

NiceGUI is a Python-based UI framework. Prior to version 3.9.0, NiceGUI's app.add_media_file() and app.add_media_files() media routes accept a user-controlled query parameter that influences how files are read during streaming. The parameter is passed to the range-response implementation without validation, allowing an attacker to bypass chunked streaming and force the server to load entire files into memory at once. With large media files and concurrent requests, this can lead to excessive memory consumption, degraded performance, or denial of service. This issue has been patched in version 3.9.0.

Affected products

VendorProductAffectedFixed
zauberzeug nicegui < 3.9.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI nicegui < 3.9.0 3.9.0 GHSA-w5g8-5849-vj76

References