How severe is CVE-2026-33175?

CVE-2026-33175 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-33175 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33175?

CVE-2026-33175 affects Jupyter Oauthenticator. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33175?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-33175 have an EU (EUVD) identifier?

Yes. CVE-2026-33175 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18878.

When was CVE-2026-33175 published?

CVE-2026-33175 was published on 2026-04-03 and last updated on 2026-06-17.

CVE-2026-33175

CVE-2026-33175 is a high-severity vulnerability in Jupyter Oauthenticator with a CVSS 3.x base score of 8.8. 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-287.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18878
Weakness: CWE-287
Affected product: Jupyter Oauthenticator
Published: 2026-04-03
Last modified: 2026-06-17

Description

OAuthenticator is software that allows OAuth2 identity providers to be plugged in and used with JupyterHub. Prior to version 17.4.0, an authentication bypass vulnerability in oauthenticator allows an attacker with an unverified email address on an Auth0 tenant to login to JupyterHub. When email is used as the usrname_claim, this gives users control over their username and the possibility of account takeover. This issue has been patched in version 17.4.0.

Frequently asked questions

What is CVE-2026-33175?: OAuthenticator is software that allows OAuth2 identity providers to be plugged in and used with JupyterHub. Prior to version 17.4.0, an authentication bypass vulnerability in oauthenticator allows an attacker with an unverified email address on an Auth0 tenant to login to JupyterHub. When email is used as the usrname_claim, this gives users control over their username and the possibility of account takeover. This issue has been patched in version 17.4.0.
How severe is CVE-2026-33175?: CVE-2026-33175 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-33175 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33175?: CVE-2026-33175 affects Jupyter Oauthenticator. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33175?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-33175 have an EU (EUVD) identifier?: Yes. CVE-2026-33175 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18878.
When was CVE-2026-33175 published?: CVE-2026-33175 was published on 2026-04-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:jupyter:oauthenticator:*:*:*:*:*:*:*:*

More vulnerabilities in Jupyter Oauthenticator

CVE-2018-7206 — High (CVSS 8.8): An issue was discovered in Project Jupyter JupyterHub OAuthenticator 0.6.x before 0.6.2 and 0.7.x before 0.7.3. When…
CVE-2024-29033 — High (CVSS 7.5): OAuthenticator provides plugins for JupyterHub to use common OAuth providers, as well as base classes for writing one's…
CVE-2020-26250 — Medium (CVSS 6.3): OAuthenticator is an OAuth login mechanism for JupyterHub. In oauthenticator from version 0.12.0 and before 0.12.2, the…
CVE-2022-31027 — Medium (CVSS 4.2): OAuthenticator is an OAuth token library for the JupyerHub login handler. CILogonOAuthenticator is provided by the…

All CVEs affecting Jupyter Oauthenticator →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →