{"schemaVersion":3,"id":"CVE-2026-102077","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series with SPC3 allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).\n\n\n\nOn MX Series with SPC3 line-card and source NAT configuration, when a specific malformed IPv6 packet is received, it is not dropped but instead a session is created and NAT resources are allocated. Continued receipt of such packets will eventually lead to session or resource exhaustion, which will impact all traffic through the device. To recover the device needs to be rebooted.\nTo monitor session usage, use the following:\n\nshow services sessions summary\n\nTo monitor source NAT resource usage, use the following:\n\nshow services nat pool\n\nThis issue affects Junos OS on MX Series with SPC3:\n\n  *  All versions before 23.2R2-S4;\n  *  23.4 versions before 23.4R2-S5;\n  *  24.2 versions before 24.2R2.","dates":{"published":"2026-10-14T17:14:01.511Z","modified":"2026-10-14T20:26:08.665Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":8.7,"severity":"high","version":"4.0","versionLabel":"v4.0","source":"CVE.org","vector":"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/AU:Y/R:U/RE:M","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"CVE.org","score":8.7,"severity":"high","vector":"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/AU:Y/R:U/RE:M","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"NVD","score":8.7,"severity":"high","vector":"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:U/V:X/RE:M/U:X","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00339,"percentile":0.25836,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[{"date":"2026-10-15T00:00:00.000Z","score":0.00339,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00339,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00339,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00339,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00339,"percentile":0.25836}],"last30":[{"date":"2026-10-15T00:00:00.000Z","score":0.00339,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00339,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00339,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00339,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00339,"percentile":0.25836}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-754","name":"Improper Check for Unusual or Exceptional Conditions","description":"The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.","type":"weakness","status":"Incomplete","abstraction":"Class","likelihoodOfExploit":"Medium","url":"https://cwe.mitre.org/data/definitions/754.html"}],"affected":[{"vendor":"juniper networks","product":"junos os","name":"Junos OS","label":"junos os","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 23.2R2-S4","noFixRecorded":false,"fixedIn":null},{"text":"≥ 23.4, < 23.4R2-S5","noFixRecorded":false,"fixedIn":null},{"text":"≥ 24.2, < 24.2R2","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 23.2R2-S4 | ≥ 23.4, < 23.4R2-S5 | ≥ 24.2, < 24.2R2","eol":null,"hubHref":"/vendor/juniper_networks/junos_os"}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://supportportal.juniper.net/JSA112182","label":"supportportal.juniper.net/JSA112182","hostname":"supportportal.juniper.net","tags":["Vendor Advisory"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-10-14T17:14:01.511Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-10-14T20:26:08.665Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":35,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T06:29:13.643Z","stale":false,"partial":false}}