{"cve":"CVE-2026-21909","nvd":{"published":"2026-01-15T21:16:06.727","modified":"2026-06-17T10:19:08.240","status":"Analyzed","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> show task memory detail | match ted-infra\n  TED-INFRA-COOKIE             25     1072       28     1184       229\n\n\n\nuser@junos> \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.","cvss_v4":{"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","score":7.1},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-401"],"references":["https://kb.juniper.net/JSA106008","https://supportportal.juniper.net/JSA106008"],"products":["juniper:junos","juniper:junos_os_evolved"],"source":"nvd","synced_at":"2026-10-19T22:19:41.481987139+00:00"},"epss":{"cve":"CVE-2026-21909","score":0.00249,"percentile":0.16304,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}