PYSEC-2026-3853

See a problem?
Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/jupyterhub/PYSEC-2026-3853.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-3853
Aliases
Published
2026-09-10T09:44:57Z
Modified
2026-09-10T12:15:03Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
JupyterHub has Unauthenticated Denial of Service via Unbounded Username Logging on Failed Login
Details

Impact

Invalid input to login resulted in unbounded logging output. Only form-based Authenticators (the default PAM Authenticator, but not the more widely used OAuthenticator) are affected.

Patches

Upgrade to 5.5.0.

Workarounds

Use an Authenticator that doesn't use a login form, such as OAuthenticator.

References

Affected packages

PyPI / jupyterhub

Package

Name
jupyterhub
View open source insights on deps.dev
Purl
pkg:pypi/jupyterhub

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
5.5.0

Affected versions

0.*
0.1.0
0.2.0
0.3.0
0.4.0
0.4.1
0.5.0
0.6.0
0.6.1
0.7.0b1
0.7.0
0.7.1
0.7.2
0.8.0b1
0.8.0b2
0.8.0b3
0.8.0b4
0.8.0b5
0.8.0rc1
0.8.0rc2
0.8.0
0.8.1
0.9.0b1
0.9.0b2
0.9.0b3
0.9.0rc1
0.9.0
0.9.1
0.9.2
0.9.3
0.9.4
0.9.5
0.9.6
1.*
1.0.0b1
1.0.0b2
1.0.0
1.1.0b1
1.1.0
1.2.0b1
1.2.0
1.2.1
1.2.2
1.3.0
1.4.0
1.4.1
1.4.2
1.5.0
1.5.1
2.*
2.0.0b1
2.0.0b2
2.0.0b3
2.0.0rc1
2.0.0rc2
2.0.0rc3
2.0.0rc4
2.0.0rc5
2.0.0
2.0.1
2.0.2
2.1.0
2.1.1
2.2.0
2.2.1
2.2.2
2.3.0
2.3.1
3.*
3.0.0b1
3.0.0
3.1.0
3.1.1
4.*
4.0.0b1
4.0.0b2
4.0.0
4.0.1
4.0.2
4.1.0
4.1.1
4.1.2
4.1.3
4.1.4
4.1.5
4.1.6
5.*
5.0.0b1
5.0.0b2
5.0.0
5.1.0
5.2.0
5.2.1
5.3.0rc0
5.3.0
5.4.0
5.4.1
5.4.2
5.4.3
5.4.4
5.4.5
5.4.6

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/jupyterhub/PYSEC-2026-3853.yaml"