LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)
Summary
The LTI 1.1 validator stores OAuth nonces in a class-level dictionary that grows without bounds. Nonces are added before signature validation, so an attacker with knowledge of a valid consumer key can send repeated requests with unique nonces to gradually exhaust server memory, causing a denial of service.
Patches
- upgrade jupyterhub-litauthenticator to 1.6.3
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | jupyterhub-ltiauthenticator | < 1.6.3 | 1.6.3 |
References
- https://github.com/jupyterhub/ltiauthenticator/security/advisories/GHSA-8mxq-7xr7-2fxj
- https://nvd.nist.gov/vuln/detail/CVE-2026-34052
- https://github.com/jupyterhub/ltiauthenticator
- https://github.com/jupyterhub/ltiauthenticator/releases/tag/1.6.3
- https://pypi.org/project/jupyterhub-ltiauthenticator
- https://github.com/advisories/GHSA-8mxq-7xr7-2fxj
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-401, CWE-770- Platform
- Python (PyPI)
- Package
jupyterhub-ltiauthenticator- Disclosed
- 03.04.2026
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-2533 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-8mxq-7xr7-2fxj - CC BY 4.0
Vulnerability history: jupyterhub-ltiauthenticator
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 02.2025 04.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- Medium 1
Disclosures per year
- 2025: 1
- 2026: 1
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LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service) this entry
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