How severe is CVE-2026-34052?

CVE-2026-34052 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-34052 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34052?

CVE-2026-34052 affects Jupyter Lti Jupyterhub Authenticator. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34052?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-34052 have an EU (EUVD) identifier?

Yes. CVE-2026-34052 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18893.

When was CVE-2026-34052 published?

CVE-2026-34052 was published on 2026-04-03 and last updated on 2026-06-17.

CVE-2026-34052

CVE-2026-34052 is a medium-severity vulnerability in Jupyter Lti Jupyterhub Authenticator with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-401.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
EPSS exploit prediction: 0% (25th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18893
Weakness: CWE-401
Affected product: Jupyter Lti Jupyterhub Authenticator
Published: 2026-04-03
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-34052?: CVE-2026-34052 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-34052 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34052?: CVE-2026-34052 affects Jupyter Lti Jupyterhub Authenticator. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34052?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34052 have an EU (EUVD) identifier?: Yes. CVE-2026-34052 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18893.
When was CVE-2026-34052 published?: CVE-2026-34052 was published on 2026-04-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:jupyter:lti_jupyterhub_authenticator:*:*:*:*:*:*:*:*

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