CVE-2026-34052: 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
Other sources
LTI JupyterHub Authenticator is a JupyterHub authenticator for LTI. Prior to version 1.6.3, 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. This issue has been patched in version 1.6.3.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
pip/jupyterhub-ltiauthenticatorto a version that resolves this vulnerability.Fixed in 1.6.3 - Upgrade
Upgrade
jupyterhub-litauthenticatorto a version that resolves this vulnerability.Fixed in 1.6.3