CVE-2026-33175 | jupyterhub oauthenticator up to 17.3.x usrname_claim improper authentication (GHSA-rrvg-cxh4-qhrv)

VDB-355273 · CVE-2026-33175 · GHSA-RRVG-CXH4-QHRV JUPYTERHUB OAUTHENTICATOR UP TO 17.3.X USRNAME_CLAIM IMPROPER AUTHENTICATION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 7.4 $0-$5k 0.31+ Summaryinfo A vulnerability identified as critical has been detected in jupyterhub oauthenticator up to 17.3.x. The affected element is an unknown function. This manipulation of the argument usrname_claim causes improper authentication. This vulnerability appears as CVE-2026-33175. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component. Detailsinfo A vulnerability was found in jupyterhub oauthenticator up to 17.3.x. It has been declared as critical. Affected by this vulnerability is some unknown functionality. The manipulation of the argument usrname_claim with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is: 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. The advisory is shared at github.com. This vulnerability is known as CVE-2026-33175 since 03/17/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. Upgrading to version 17.4.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch f0c7002dc36e41efae0f674033cf7888a21d96f9 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version. Productinfo Vendor jupyterhub Name oauthenticator Version 17.0 17.1 17.2 17.3 License open-source Website Product: https://github.com/jupyterhub/oauthenticator/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 7.6 VulDB Meta Temp Score: 7.4 VulDB Base Score: 6.3 VulDB Temp Score: 6.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 8.8 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Improper authentication CWE: CWE-287 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: oauthenticator 17.4.0 Patch: f0c7002dc36e41efae0f674033cf7888a21d96f9 Timelineinfo 03/17/2026 CVE reserved 04/04/2026 +17 days Advisory disclosed 04/04/2026 +0 days VulDB entry created 04/04/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: GHSA-rrvg-cxh4-qhrv Status: Confirmed CVE: CVE-2026-33175 (🔒) GCVE (CVE): GCVE-0-2026-33175 GCVE (VulDB): GCVE-100-355273 Entryinfo Created: 04/04/2026 08:09 Changes: 04/04/2026 08:09 (68) Complete: 🔍 Cache ID: 99:F19:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸