CVE-2026-34052: Jupyter Lti Jupyterhub Authenticator

Medium severity, CVSS 5.9. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Jupyter Lti Jupyterhub Authenticator: before 1.6.3 (fixed in 1.6.3)

Published 2026-04-03. Last modified 2026-07-24.