JupyterHub: Unauthenticated Denial of Service via Unbounded Username Logging on Failed Login
JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. Prior to 5.5.0, invalid input to form-based login authenticators can place an unbounded attacker-controlled username in failed-login logs, allowing an unauthenticated attacker to consume logging and storage resources. This issue is fixed in version 5.5.0.
BIT-jupyterhub-2026-54338
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:BIT-jupyterhub-2026-54338
jupyterhub
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 5.5.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.5.0"
}
]
}
],
"package": {
"name": "jupyterhub",
"purl": "pkg:bitnami/jupyterhub",
"ecosystem": "Bitnami"
},
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
}
],
"database_specific": {
"source": "https://github.com/bitnami/vulndb/tree/main/data/jupyterhub/BIT-jupyterhub-2026-54338.json"
}
}
]- Related CVEs
- CVE-2026-54338
Source reference:
/aliases
Publisher severity
medium
Source reference: /database_specific/severity
- Event
- #25980 · Revision 1
- Added to Heist Feed
- Publisher date