{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-21909", "assignerOrgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968", "state": "PUBLISHED", "assignerShortName": "juniper", "dateReserved": "2026-01-05T17:32:48.710Z", "datePublished": "2026-01-15T20:22:44.674Z", "dateUpdated": "2026-01-15T20:52:42.400Z" }, "containers": { "cna": { "affected": [ { "defaultStatus": "unaffected", "product": "Junos OS", "vendor": "Juniper Networks", "versions": [ { "lessThan": "23.2R2", "status": "affected", "version": "23.2", "versionType": "semver" }, { "lessThan": "23.4R1-S2, 23.4R2", "status": "affected", "version": "23.4", "versionType": "semver" }, { "lessThan": "24.1R2", "status": "affected", "version": "24.1", "versionType": "semver" }, { "lessThan": "23.2R1", "status": "unaffected", "version": "0", "versionType": "semver" } ] }, { "defaultStatus": "unaffected", "product": "Junos OS Evolved", "vendor": "Juniper Networks", "versions": [ { "lessThan": "23.2R2-EVO", "status": "affected", "version": "23.2", "versionType": "semver" }, { "lessThan": "23.4R1-S2-EVO, 23.4R2-EVO", "status": "affected", "version": "23.4", "versionType": "semver" }, { "lessThan": "24.1R2-EVO", "status": "affected", "version": "24.1", "versionType": "semver" }, { "lessThan": "23.2R1-EVO", "status": "unaffected", "version": "0", "versionType": "semver" } ] } ], "configurations": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "This issue affects systems with IS-IS configured. For example:

[protocols isis interface lo.0 ...]
\n\n[protocols isis interface <interface> ...]
[interfaces <interface> unit <n> family iso]
" } ], "value": "This issue affects systems with IS-IS configured. For example:\n\n[protocols isis interface lo.0 ...]\n\n\n[protocols isis interface ...]\n[interfaces unit family iso]" } ], "datePublic": "2026-01-14T17:00:00.000Z", "descriptions": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "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.

Memory usage can be monitored through the use of the 'show task memory detail' command. For example:

user@junos> show task memory detail | match ted-infra
  TED-INFRA-COOKIE           25   1072     28   1184     229

\n\nuser@junos> \n\nshow task memory detail | match ted-infra
  TED-INFRA-COOKIE           31   1360     34   1472     307


This issue affects:

Junos OS: 

  • from 23.2 before 23.2R2, 
  • from 23.4 before 23.4R1-S2, 23.4R2, 
  • from 24.1 before 24.1R2; 

Junos OS Evolved: 

  • from 23.2 before 23.2R2-EVO, 
  • from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO, 
  • from 24.1 before 24.1R2-EVO.
This issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO." } ], "value": "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." } ], "exploits": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "Juniper SIRT is not aware of any malicious exploitation of this vulnerability." } ], "value": "Juniper SIRT is not aware of any malicious exploitation of this vulnerability." } ], "metrics": [ { "cvssV3_1": { "attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ] }, { "cvssV4_0": { "Automatable": "YES", "Recovery": "AUTOMATIC", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "ADJACENT", "baseScore": 7.1, "baseSeverity": "HIGH", "privilegesRequired": "NONE", "providerUrgency": "GREEN", "subAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "CONCENTRATED", "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/AU:Y/R:A/V:C/RE:M/U:Green", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "MODERATE" }, "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ] } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-401", "description": "CWE-401 Missing Release of Memory after Effective Lifetime", "lang": "en", "type": "CWE" } ] } ], "providerMetadata": { "orgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968", "shortName": "juniper", "dateUpdated": "2026-01-15T20:22:44.674Z" }, "references": [ { "tags": [ "vendor-advisory" ], "url": "https://supportportal.juniper.net/JSA106008" }, { "tags": [ "vendor-advisory" ], "url": "https://kb.juniper.net/JSA106008" } ], "solutions": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "The following software releases have been updated to resolve this specific issue:
Junos OS: 23.2R2, 23.4R1-S2, 23.4R2, 24.1R2, 24.2R1, and all subsequent releases.\n\n
Junos OS Evolved: 23.2R2-EVO, 23.4R1-S2-EVO, 23.4R2-EVO, 24.1R2-EVO, 24.2R1-EVO, and all subsequent releases.\n\n


" } ], "value": "The following software releases have been updated to resolve this specific issue:\nJunos OS: 23.2R2, 23.4R1-S2, 23.4R2, 24.1R2, 24.2R1, and all subsequent releases.\n\n\n Junos OS Evolved: 23.2R2-EVO, 23.4R1-S2-EVO, 23.4R2-EVO, 24.1R2-EVO, 24.2R1-EVO, and all subsequent releases." } ], "source": { "advisory": "JSA106008", "defect": [ "1793982" ], "discovery": "USER" }, "title": "Junos OS and Junos OS Evolved: Receipt of specific IS-IS update packet causes memory leak leading to RPD crash", "workarounds": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "There are no known workarounds for this issue." } ], "value": "There are no known workarounds for this issue." } ], "x_generator": { "engine": "Vulnogram 0.1.0-dev" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-01-15T20:52:37.531214Z", "id": "CVE-2026-21909", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-15T20:52:42.400Z" } } ] } }