CVE-2025-21618

NiceGUI On Air authentication issue

7.5 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: High
Availability: None

Exploit likelihood

0.39%Up 0.3 points since Jan 7, 2025

What each source reports

CVE List Score used 7.5

NiceGUI On Air authentication issue

Record: CVE-2025-21618
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness: CWE-287
Updated: 2026-11-02

EUVDEUVD-2025-0044 7.5

Record: EUVD-2025-0044
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Updated: 2026-11-03

GitHub AdvisoriesGHSA-v6jv-p6r8-j78w 7.5

NiceGUI On Air authentication issue

Summary

Once a user logins to one browser, all other browsers are logged in without entering password. Even incognito mode.

Impact

high

Record: GHSA-v6jv-p6r8-j78w
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness: CWE-287
Updated: 2026-11-02

NVD 7.5

Record: CVE-2025-21618
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness: CWE-287
Updated: 2026-11-02

OSV 7.5

NiceGUI On Air authentication issue

Record: CVE-2025-21618
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness: CWE-287
Updated: 2026-11-02

OSVGHSA-v6jv-p6r8-j78w 7.5

NiceGUI On Air authentication issue

Summary

Once a user logins to one browser, all other browsers are logged in without entering password. Even incognito mode.

Impact

high

Record: GHSA-v6jv-p6r8-j78w
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness: CWE-287
Updated: 2026-11-02

OSVPYSEC-2026-1705 7.5

NiceGUI On Air authentication issue

Summary

Once a user logins to one browser, all other browsers are logged in without entering password. Even incognito mode.

Impact

high

Record: PYSEC-2026-1705
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Updated: 2026-11-02

Affected products

zauberzeug nicegui

Affected packages

Affected packages
Package	Affected	Fixed
`nicegui` PyPI	through 2.9.0	2.9.1
`nicegui` PyPI	before 2.9.1, plus listed versions 0.1.00.1.40.1.60.2.00.2.1 Show 45 moreShow less 0.2.100.2.110.2.120.2.130.2.140.2.150.2.20.2.30.2.40.2.90.3.00.3.10.3.20.3.30.3.40.3.50.3.60.3.70.3.80.3.90.4.00.4.10.4.100.4.110.4.120.4.130.4.140.4.150.4.20.4.30.4.40.4.50.4.60.4.70.4.80.4.90.5.00.5.10.5.100.5.110.5.120.5.20.5.30.5.40.5.5	2.9.1

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2025-21618 is a high vulnerability (CVSS 7.5) in Zauberzeug Nicegui, published January 6, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.39%, the 33rd percentile. Fixed in nicegui 2.9.1.

References

This page doesn't list everything

Left out here: 206 versions. The JSON record has them.