PYSEC-2026-2533 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...

CVE-2026-34052

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...

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...

LTI JupyterHub Authenticator does not properly validate JWT Signature

Impact Only users that has configured a JupyterHub installation to use the authenticator class LTI13Authenticator are influenced. LTI13Authenticator that was introduced in jupyterhub-ltiauthenticator 1.3.0 wasn't validating JWT signatures. This is believed to allow the LTI13Authenticator to...