What is CVE-2026-34052?

CVE-2026-34052 is a medium-severity vulnerability in Jupyter Lti Jupyterhub Authenticator, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.9/10. Published 2026-04-03.

How severe is CVE-2026-34052?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Resource exhaustion in Jupyter Lti Jupyterhub Authenticator

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 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.

Published 2026-04-03 · last modified 2026-07-24.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (32.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 32.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Jupyter Lti Jupyterhub Authenticator
Jupyterhub Ltiauthenticator — versions < 1.6.3

Weakness classification (CWE)

References

github.com/jupyterhub/ltiauthenticator/security/advisories/GHSA-8mxq-7xr7-2fxj (Vendor Advisory)
github.com/jupyterhub/ltiauthenticator/releases/tag/1.6.3 (Product)

Frequently asked questions

What is CVE-2026-34052?: CVE-2026-34052 is a medium-severity vulnerability in Jupyter Lti Jupyterhub Authenticator, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.9/10. Published 2026-04-03.
How severe is CVE-2026-34052?: Medium severity. CVSS v3 base score is 5.9 out of 10.