CVE-2026-54338

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Source
https://cve.org/CVERecord?id=CVE-2026-54338
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54338.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-54338
Aliases
  • GHSA-p43p-whwx-q52h
Downstream
Published
2026-08-07T20:52:55.068Z
Modified
2026-08-12T03:51:29.896100389Z
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: Unauthenticated Denial of Service via Unbounded Username Logging on Failed Login
Details

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.

Database specific 
{
    "cwe_ids": [
        "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54338.json",
    "cna_assigner": "GitHub_M",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "< 5.5.0JupyterHub 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."
                },
                {
                    "last_affected": "< 5.5.0JupyterHub 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."
                }
            ]
        }
    ]
}
References

Affected packages

Git / github.com/jupyterhub/jupyterhub

Affected ranges

Type
GIT
Repo
https://github.com/jupyterhub/jupyterhub
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
d6dc595f84b7509969686da31d87d6d69e7fce0a
Database specific
Show details 
{
    "source": "REFERENCES"
}

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
0.7.0
0.7.1
0.7.2
0.8.0
0.8.0b1
0.8.0b2
0.8.0b3
0.8.0b4
0.8.0b5
0.8.0rc1
0.8.0rc2
0.8.1
0.9.0
0.9.0b1
0.9.0b2
0.9.0b3
0.9.0rc1
0.9.1
0.9.2
1.*
1.0.0
1.0.0b1
1.0.0b2
1.1.0
1.1.0b1
1.2.0
1.2.0b1
1.2.1
1.3.0
1.4.0
2.*
2.0.0
2.0.0b1
2.0.0b2
2.0.0b3
2.0.0rc1
2.0.0rc2
2.0.0rc3
2.0.0rc4
2.0.0rc5
2.0.1
2.0.2
2.1.0
2.1.1
2.2.0
2.2.1
2.2.2
3.*
3.0.0
3.0.0b1
3.1.0
4.*
4.0.0
4.0.0b1
4.0.0b2
4.0.1
5.*
5.0.0
5.0.0b1
5.0.0b2
5.1.0
5.2.0
5.2.1
5.3.0
5.3.0rc0
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://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54338.json"