LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service) (CVE-2026-34052) | HOL Guard CVE

Medium · CVSS 5.9CVE-2026-34052GHSA-8MXQ-7XR7-2FXJ

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

Answer in brief

CVE-2026-34052 records a Medium severity (CVSS 5.9) vulnerability in LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service). The current sources do not mark it as known exploited. The current feed maps jupyterhub-ltiauthenticator (pypi). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Apr 3, 2026Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Sep 10, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.9
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps jupyterhub-ltiauthenticator (pypi). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
jupyterhub-ltiauthenticatorpypi	>=0 <1.6.3	1.6.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for jupyterhub-ltiauthenticator.
Review the reported fix. Update jupyterhub-ltiauthenticator to 1.6.3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Apr 3, 2026
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Sep 10, 2026

Sources and claim methodology

Upstream source description

## 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

Quoted source text, attributed separately from HOL analysis.