CVE-2026-34052

LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)

MEDIUM
5.9
CVSS Score
Published: April 3, 2026 at 10:04 PM UTC
Updated: July 24, 2026 at 10:20 PM UTC
2 products affected across 2 vendorsLti Jupyterhub AuthenticatorLti Jupyterhub Authenticator

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.6.3
Affected range stops below 1.6.3, so it looks safe — our inference, not a vendor statement
v < 1.6.3
Affected range stops below 1.6.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-401CWE-770

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