{"id":"CVE-2026-21909","aliases":["EUVD-2026-2696","GHSA-cf3w-5gm7-wvp9"],"status":"published","title":"Junos OS and Junos OS Evolved: Receipt of specific IS-IS update packet causes memory leak leading to RPD crash","description":"A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated attacker controlling an adjacent IS-IS neighbor to send a specific update packet causing a memory leak. Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition.\n\nMemory usage can be monitored through the use of the 'show task memory detail' command. For example:\n\nuser@junos\u003e show task memory detail | match ted-infra\n  TED-INFRA-COOKIE             25     1072       28     1184       229\n\n\n\nuser@junos\u003e \n\nshow task memory detail | match ted-infra\n  TED-INFRA-COOKIE             31     1360       34     1472       307\n\nThis issue affects:\n\nJunos OS: \n\n  *  from 23.2 before 23.2R2, \n  *  from 23.4 before 23.4R1-S2, 23.4R2, \n  *  from 24.1 before 24.1R2; \n\n\nJunos OS Evolved: \n\n  *  from 23.2 before 23.2R2-EVO, \n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO, \n  *  from 24.1 before 24.1R2-EVO.\n\n\nThis issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO.","severity":{"version":"4.0","score":7.1,"vector":"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/AU:Y/R:A/V:C/RE:M/U:Green","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00249,"percentile":0.16332,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-401"],"published":"2026-01-15T20:22:44Z","modified":"2026-06-17T10:19:08Z","products":[{"vendor":"juniper","product":"junos"},{"vendor":"juniper","product":"junos_os_evolved"},{"vendor":"juniper networks","product":"junos os"},{"vendor":"juniper networks","product":"junos os evolved"}],"references":[{"url":"https://supportportal.juniper.net/JSA106008","tags":["vendor-advisory","Vendor Advisory"]},{"url":"https://kb.juniper.net/JSA106008","tags":["vendor-advisory","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-21909"},{"url":"https://github.com/advisories/GHSA-cf3w-5gm7-wvp9"}],"sources":{"cve":[{"id":"CVE-2026-21909","title":"Junos OS and Junos OS Evolved: Receipt of specific IS-IS update packet causes memory leak leading to RPD crash","description":"A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated attacker controlling an adjacent IS-IS neighbor to send a specific update packet causing a memory leak. Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition.\n\nMemory usage can be monitored through the use of the 'show task memory detail' command. For example:\n\nuser@junos\u003e show task memory detail | match ted-infra\n  TED-INFRA-COOKIE             25     1072       28     1184       229\n\n\n\nuser@junos\u003e \n\nshow task memory detail | match ted-infra\n  TED-INFRA-COOKIE             31     1360       34     1472       307\n\nThis issue affects:\n\nJunos OS: \n\n  *  from 23.2 before 23.2R2, \n  *  from 23.4 before 23.4R1-S2, 23.4R2, \n  *  from 24.1 before 24.1R2; \n\n\nJunos OS Evolved: \n\n  *  from 23.2 before 23.2R2-EVO, \n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO, \n  *  from 24.1 before 24.1R2-EVO.\n\n\nThis issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO.","status":"published","published":"2026-01-15T20:22:44.674Z","modified":"2026-01-15T20:52:42.4Z","cvss":[{"version":"4.0","score":7.1,"vector":"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/AU:Y/R:A/V:C/RE:M/U:Green","level":"high","assessor":"cna"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T13:41:53.237769Z"}],"euvd":[{"id":"EUVD-2026-2696","description":"A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated attacker controlling an adjacent IS-IS neighbor to send a specific update packet causing a memory leak. Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition.\n\nMemory usage can be monitored through the use of the 'show task memory detail' command. For example:\n\nuser@junos\u003e show task memory detail | match ted-infra\n  TED-INFRA-COOKIE             25     1072       28     1184       229\n\n\n\nuser@junos\u003e \n\nshow task memory detail | match ted-infra\n  TED-INFRA-COOKIE             31     1360       34     1472       307\n\nThis issue affects:\n\nJunos OS: \n\n  *  from 23.2 before 23.2R2, \n  *  from 23.4 before 23.4R1-S2, 23.4R2, \n  *  from 24.1 before 24.1R2; \n\n\nJunos OS Evolved: \n\n  *  from 23.2 before 23.2R2-EVO, \n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO, \n  *  from 24.1 before 24.1R2-EVO.\n\n\nThis issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO.","status":"published","published":"2026-01-15T20:22:44Z","modified":"2026-01-15T20:52:42Z","cvss":[{"version":"4.0","score":7.1,"vector":"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/AU:Y/R:A/V:C/RE:M/U:Green","level":"high"}],"updated_at":"2026-11-02T19:48:51.36047Z"}],"ghsa":[{"id":"GHSA-cf3w-5gm7-wvp9","title":"A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon...","description":"A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated attacker controlling an adjacent IS-IS neighbor to send a specific update packet causing a memory leak. Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition.\n\nMemory usage can be monitored through the use of the 'show task memory detail' command. For example:\n\nuser@junos\u003e show task memory detail | match ted-infra\n  TED-INFRA-COOKIE             25     1072       28     1184       229\n\n\n\nuser@junos\u003e \n\nshow task memory detail | match ted-infra\n  TED-INFRA-COOKIE             31     1360       34     1472       307\n\nThis issue affects:\n\nJunos OS: \n\n  *  from 23.2 before 23.2R2, \n  *  from 23.4 before 23.4R1-S2, 23.4R2, \n  *  from 24.1 before 24.1R2; \n\n\nJunos OS Evolved: \n\n  *  from 23.2 before 23.2R2-EVO, \n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO, \n  *  from 24.1 before 24.1R2-EVO.\n\n\nThis issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO.","status":"published","published":"2026-01-15T21:31:48Z","modified":"2026-01-15T21:31:55Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"},{"version":"4.0","score":7.1,"vector":"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","level":"high"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T15:05:38.149378Z"}],"nvd":[{"id":"CVE-2026-21909","description":"A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated attacker controlling an adjacent IS-IS neighbor to send a specific update packet causing a memory leak. Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition.\n\nMemory usage can be monitored through the use of the 'show task memory detail' command. For example:\n\nuser@junos\u003e show task memory detail | match ted-infra\n  TED-INFRA-COOKIE             25     1072       28     1184       229\n\n\n\nuser@junos\u003e \n\nshow task memory detail | match ted-infra\n  TED-INFRA-COOKIE             31     1360       34     1472       307\n\nThis issue affects:\n\nJunos OS: \n\n  *  from 23.2 before 23.2R2, \n  *  from 23.4 before 23.4R1-S2, 23.4R2, \n  *  from 24.1 before 24.1R2; \n\n\nJunos OS Evolved: \n\n  *  from 23.2 before 23.2R2-EVO, \n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO, \n  *  from 24.1 before 24.1R2-EVO.\n\n\nThis issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO.","status":"published","published":"2026-01-15T21:16:06.727Z","modified":"2026-06-17T10:19:08.24Z","cvss":[{"version":"4.0","score":7.1,"vector":"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","level":"high","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T14:12:04.066712Z"}]}}