GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-21909 (GCVE-0-2026-21909)

Vulnerability from cvelistv5 – Published: 2026-01-15 20:22 – Updated: 2026-01-15 20:52
VLAI
Title
Junos OS and Junos OS Evolved: Receipt of specific IS-IS update packet causes memory leak leading to RPD crash
Summary
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 user@junos> show 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.
Severity
6.5 (Medium)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.1 (High)
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
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-01-15 20:52 UTC
CWE
  • CWE-401 - Missing Release of Memory after Effective Lifetime
Assigner
References
Impacted products
Vendor Product Version CPE status
Juniper Networks Junos OS Affected: 23.2 , < 23.2R2 (semver)
Affected: 23.4 , < 23.4R1-S2, 23.4R2 (semver)
Affected: 24.1 , < 24.1R2 (semver)
Unaffected: 0 , < 23.2R1 (semver)
guessed Create a notification for this product.
Juniper Networks Junos OS Evolved Affected: 23.2 , < 23.2R2-EVO (semver)
Affected: 23.4 , < 23.4R1-S2-EVO, 23.4R2-EVO (semver)
Affected: 24.1 , < 24.1R2-EVO (semver)
Unaffected: 0 , < 23.2R1-EVO (semver)
guessed Create a notification for this product.
Date Public
2026-01-14 17:00
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-21909",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-15T20:52:37.531214Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-15T20:52:42.400Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "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:\u003cbr\u003e\u003cbr\u003e\u003ctt\u003e[protocols isis interface lo.0 ...]\u003cbr\u003e\n\n[protocols isis interface \u0026lt;interface\u0026gt; ...]\u003cbr\u003e[interfaces \u0026lt;interface\u0026gt; unit \u0026lt;n\u0026gt; family iso]\u003c/tt\u003e"
            }
          ],
          "value": "This issue affects systems with IS-IS configured. For example:\n\n[protocols isis interface lo.0 ...]\n\n\n[protocols isis interface \u003cinterface\u003e ...]\n[interfaces \u003cinterface\u003e unit \u003cn\u003e 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.\u0026nbsp;Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition.\u003cbr\u003e\u003cbr\u003eMemory usage can be monitored through the use of the \u0027show task memory detail\u0027 command. For example:\u003cbr\u003e\u003cbr\u003e\u003ctt\u003euser@junos\u0026gt; show task memory detail | match ted-infra\u003cbr\u003e\u0026nbsp; TED-INFRA-COOKIE  \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;  25  \u0026nbsp;  1072  \u0026nbsp; \u0026nbsp;  28  \u0026nbsp;  1184  \u0026nbsp; \u0026nbsp;  229\u003cbr\u003e\u003c/tt\u003e\u003cbr\u003e\n\n\u003ctt\u003euser@junos\u0026gt; \n\nshow task memory detail | match ted-infra\u003cbr\u003e\u0026nbsp; TED-INFRA-COOKIE  \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;  \u003cb\u003e\u003cspan style=\"background-color: rgb(239, 250, 102);\"\u003e31\u003c/span\u003e\u003c/b\u003e  \u0026nbsp;  \u003cb\u003e\u003cspan style=\"background-color: rgb(239, 250, 102);\"\u003e1360\u003c/span\u003e\u003c/b\u003e  \u0026nbsp; \u0026nbsp;  34  \u0026nbsp;  1472  \u0026nbsp; \u0026nbsp;  307\u003c/tt\u003e\u003cbr\u003e\u003cbr\u003e\u003cp\u003eThis issue affects:\u003c/p\u003e\u003cp\u003eJunos OS:\u0026nbsp;\u003c/p\u003e\u003cul\u003e\u003cli\u003efrom 23.2 before 23.2R2,\u0026nbsp;\u003c/li\u003e\u003cli\u003efrom 23.4 before 23.4R1-S2, 23.4R2,\u0026nbsp;\u003c/li\u003e\u003cli\u003efrom 24.1 before 24.1R2;\u0026nbsp;\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eJunos OS Evolved:\u0026nbsp;\u003c/p\u003e\u003cul\u003e\u003cli\u003efrom 23.2 before 23.2R2-EVO,\u0026nbsp;\u003c/li\u003e\u003cli\u003efrom 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO,\u0026nbsp;\u003c/li\u003e\u003cli\u003efrom 24.1 before 24.1R2-EVO.\u003c/li\u003e\u003c/ul\u003eThis 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.\u00a0Continued 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 \u0027show task memory detail\u0027 command. For example:\n\nuser@junos\u003e show task memory detail | match ted-infra\n\u00a0 TED-INFRA-COOKIE  \u00a0 \u00a0 \u00a0 \u00a0 \u00a0  25  \u00a0  1072  \u00a0 \u00a0  28  \u00a0  1184  \u00a0 \u00a0  229\n\n\n\nuser@junos\u003e \n\nshow task memory detail | match ted-infra\n\u00a0 TED-INFRA-COOKIE  \u00a0 \u00a0 \u00a0 \u00a0 \u00a0  31  \u00a0  1360  \u00a0 \u00a0  34  \u00a0  1472  \u00a0 \u00a0  307\n\nThis issue affects:\n\nJunos OS:\u00a0\n\n  *  from 23.2 before 23.2R2,\u00a0\n  *  from 23.4 before 23.4R1-S2, 23.4R2,\u00a0\n  *  from 24.1 before 24.1R2;\u00a0\n\n\nJunos OS Evolved:\u00a0\n\n  *  from 23.2 before 23.2R2-EVO,\u00a0\n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO,\u00a0\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": {
        "dateUpdated": "2026-01-15T20:22:44.674Z",
        "orgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968",
        "shortName": "juniper"
      },
      "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:\u003cbr\u003eJunos OS:\u0026nbsp;23.2R2, 23.4R1-S2, 23.4R2, 24.1R2, 24.2R1\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e, and all subsequent releases.\u003c/span\u003e\n\n\u003cbr\u003e Junos OS Evolved:\u0026nbsp;23.2R2-EVO, 23.4R1-S2-EVO, 23.4R2-EVO, 24.1R2-EVO, 24.2R1-EVO,\u0026nbsp;\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eand all subsequent releases.\u003c/span\u003e\n\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e"
            }
          ],
          "value": "The following software releases have been updated to resolve this specific issue:\nJunos OS:\u00a023.2R2, 23.4R1-S2, 23.4R2, 24.1R2, 24.2R1, and all subsequent releases.\n\n\n Junos OS Evolved:\u00a023.2R2-EVO, 23.4R1-S2-EVO, 23.4R2-EVO, 24.1R2-EVO, 24.2R1-EVO,\u00a0and 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"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968",
    "assignerShortName": "juniper",
    "cveId": "CVE-2026-21909",
    "datePublished": "2026-01-15T20:22:44.674Z",
    "dateReserved": "2026-01-05T17:32:48.710Z",
    "dateUpdated": "2026-01-15T20:52:42.400Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-21909",
      "date": "2026-09-17",
      "epss": "0.00255",
      "percentile": "0.17302"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-21909\",\"sourceIdentifier\":\"sirt@juniper.net\",\"published\":\"2026-01-15T21:16:06.727\",\"lastModified\":\"2026-06-17T10:19:08.240\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"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.\u00a0Continued 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 \u0027show task memory detail\u0027 command. For example:\\n\\nuser@junos\u003e show task memory detail | match ted-infra\\n\u00a0 TED-INFRA-COOKIE  \u00a0 \u00a0 \u00a0 \u00a0 \u00a0  25  \u00a0  1072  \u00a0 \u00a0  28  \u00a0  1184  \u00a0 \u00a0  229\\n\\n\\n\\nuser@junos\u003e \\n\\nshow task memory detail | match ted-infra\\n\u00a0 TED-INFRA-COOKIE  \u00a0 \u00a0 \u00a0 \u00a0 \u00a0  31  \u00a0  1360  \u00a0 \u00a0  34  \u00a0  1472  \u00a0 \u00a0  307\\n\\nThis issue affects:\\n\\nJunos OS:\u00a0\\n\\n  *  from 23.2 before 23.2R2,\u00a0\\n  *  from 23.4 before 23.4R1-S2, 23.4R2,\u00a0\\n  *  from 24.1 before 24.1R2;\u00a0\\n\\n\\nJunos OS Evolved:\u00a0\\n\\n  *  from 23.2 before 23.2R2-EVO,\u00a0\\n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO,\u00a0\\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.\"},{\"lang\":\"es\",\"value\":\"Una vulnerabilidad de Missing Release of Memory after Effective Lifetime en el demonio del protocolo de enrutamiento (rpd) de Juniper Networks Junos OS y Junos OS Evolved permite a un atacante no autenticado que controla un vecino IS-IS adyacente enviar un paquete de actualizaci\u00f3n espec\u00edfico causando una fuga de memoria. La recepci\u00f3n y el procesamiento continuos de estos paquetes agotar\u00e1n toda la memoria disponible, bloqueando rpd y creando una condici\u00f3n de denegaci\u00f3n de servicio (DoS).\\n\\nEl uso de la memoria se puede monitorear mediante el uso del comando \u0027show task memory detail\u0027. Por ejemplo:\\n\\nuser@junos\u0026gt; show task memory detail | match ted-infra\\n\u0026#xa0; TED-INFRA-COOKIE  \u0026#xa0; \u0026#xa0; \u0026#xa0; \u0026#xa0; \u0026#xa0;  25  \u0026#xa0;  1072  \u0026#xa0; \u0026#xa0;  28  \u0026#xa0;  1184  \u0026#xa0; \u0026#xa0;  229\\n\\n\\n\\nuser@junos\u0026gt; \\n\\nshow task memory detail | match ted-infra\\n\u0026#xa0; TED-INFRA-COOKIE  \u0026#xa0; \u0026#xa0; \u0026#xa0; \u0026#xa0; \u0026#xa0;  31  \u0026#xa0;  1360  \u0026#xa0; \u0026#xa0;  34  \u0026#xa0;  1472  \u0026#xa0; \u0026#xa0;  307\\n\\nEste problema afecta a:\\n\\nJunos OS:\\n\\n  *  desde 23.2 anterior a 23.2R2,\\n  *  desde 23.4 anterior a 23.4R1-S2, 23.4R2,\\n  *  desde 24.1 anterior a 24.1R2;\\n\\nJunos OS Evolved:\\n\\n  *  desde 23.2 anterior a 23.2R2-EVO,\\n  *  desde 23.4 anterior a 23.4R1-S2-EVO, 23.4R2-EVO,\\n  *  desde 24.1 anterior a 24.1R2-EVO.\\n\\nEste problema no afecta a las versiones de Junos OS anteriores a 23.2R1 ni a las versiones de Junos OS Evolved anteriores a 23.2R1-EVO.\"}],\"affected\":[{\"source\":\"sirt@juniper.net\",\"affectedData\":[{\"vendor\":\"Juniper Networks\",\"product\":\"Junos OS\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"23.2\",\"lessThan\":\"23.2R2\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"23.4\",\"lessThan\":\"23.4R1-S2, 23.4R2\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"24.1\",\"lessThan\":\"24.1R2\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"23.2R1\",\"versionType\":\"semver\",\"status\":\"unaffected\"}]},{\"vendor\":\"Juniper Networks\",\"product\":\"Junos OS Evolved\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"23.2\",\"lessThan\":\"23.2R2-EVO\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"23.4\",\"lessThan\":\"23.4R1-S2-EVO, 23.4R2-EVO\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"24.1\",\"lessThan\":\"24.1R2-EVO\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"23.2R1-EVO\",\"versionType\":\"semver\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"sirt@juniper.net\",\"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\":\"sirt@juniper.net\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":6.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"ADJACENT_NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-01-15T20:52:37.531214Z\",\"id\":\"CVE-2026-21909\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"sirt@juniper.net\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-401\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"1A78CC80-E8B1-4CDA-BB35-A61833657FA7\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:*\",\"matchCriteriaId\":\"4B3B2FE1-C228-46BE-AC76-70C2687050AE\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:*\",\"matchCriteriaId\":\"F1B16FF0-900F-4AEE-B670-A537139F6909\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:*\",\"matchCriteriaId\":\"B227E831-30FF-4BE1-B8B2-31829A5610A6\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"78481ABC-3620-410D-BC78-334657E0BB75\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:*\",\"matchCriteriaId\":\"BE8A5BA3-87BD-473A-B229-2AAB2C797005\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:*\",\"matchCriteriaId\":\"8B74AC3E-8FC9-400A-A176-4F7F21F10756\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:*\",\"matchCriteriaId\":\"175CCB13-76C0-44A4-A71D-41E22B92EB23\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:24.1:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"58C99F21-D87E-48FD-85EF-9A5EF6DE53B7\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos:24.1:r1:*:*:*:*:*:*\",\"matchCriteriaId\":\"0EA5E5D6-F7B5-46BE-B96D-F64CCEAF08F2\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:23.2:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"6DEAA7FD-385F-4221-907E-65ABC16BE4BE\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:23.2:r1:*:*:*:*:*:*\",\"matchCriteriaId\":\"DDEC008A-3137-48D1-8ABC-6DB0EFC40E50\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:23.2:r1-s1:*:*:*:*:*:*\",\"matchCriteriaId\":\"558D234D-BC50-415F-86D6-8E19D6C3ACE0\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:23.2:r1-s2:*:*:*:*:*:*\",\"matchCriteriaId\":\"33F4EEEE-77E9-4973-A770-99E7BA2F05F5\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:23.4:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"9D7F0D73-85EE-4A07-B51B-6BF52ECBA75E\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:23.4:r1:*:*:*:*:*:*\",\"matchCriteriaId\":\"FE777A1F-9CD9-426E-AF1C-FBE01EB9A4A8\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:23.4:r1-s1:*:*:*:*:*:*\",\"matchCriteriaId\":\"7147BA60-30A5-4CED-9AAF-F6BEA0528B89\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:23.4:r2:*:*:*:*:*:*\",\"matchCriteriaId\":\"FB82B22F-9005-4EF0-A1E3-4261757783D4\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:24.1:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"8E41F858-24E8-4986-BED6-BE5151219DEC\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:juniper:junos_os_evolved:24.1:r1:*:*:*:*:*:*\",\"matchCriteriaId\":\"EE57490C-2800-4456-8293-B54A255CF348\"}]}]}],\"references\":[{\"url\":\"https://kb.juniper.net/JSA106008\",\"source\":\"sirt@juniper.net\",\"tags\":[\"Vendor Advisory\"]},{\"url\":\"https://supportportal.juniper.net/JSA106008\",\"source\":\"sirt@juniper.net\",\"tags\":[\"Vendor Advisory\"]}]}}",
    "redhat_vex": {
      "current_release_date": "2026-01-16T21:33:34+00:00",
      "cve": "CVE-2026-21909",
      "id": "CVE-2026-21909",
      "initial_release_date": "2026-01-14T17:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "Junos OS and Junos OS Evolved: Receipt of specific IS-IS update packet causes memory leak leading to RPD crash",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21909.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-21909\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-01-15T20:52:37.531214Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-01-15T20:52:39.114Z\"}}], \"cna\": {\"title\": \"Junos OS and Junos OS Evolved: Receipt of specific IS-IS update packet causes memory leak leading to RPD crash\", \"source\": {\"defect\": [\"1793982\"], \"advisory\": \"JSA106008\", \"discovery\": \"USER\"}, \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 6.5, \"attackVector\": \"ADJACENT_NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}, {\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"AUTOMATIC\", \"baseScore\": 7.1, \"Automatable\": \"YES\", \"attackVector\": \"ADJACENT\", \"baseSeverity\": \"HIGH\", \"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\", \"providerUrgency\": \"GREEN\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"LOW\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"NONE\", \"vulnerabilityResponseEffort\": \"MODERATE\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"Juniper Networks\", \"product\": \"Junos OS\", \"versions\": [{\"status\": \"affected\", \"version\": \"23.2\", \"lessThan\": \"23.2R2\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"23.4\", \"lessThan\": \"23.4R1-S2, 23.4R2\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"24.1\", \"lessThan\": \"24.1R2\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"23.2R1\", \"versionType\": \"semver\"}], \"defaultStatus\": \"unaffected\"}, {\"vendor\": \"Juniper Networks\", \"product\": \"Junos OS Evolved\", \"versions\": [{\"status\": \"affected\", \"version\": \"23.2\", \"lessThan\": \"23.2R2-EVO\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"23.4\", \"lessThan\": \"23.4R1-S2-EVO, 23.4R2-EVO\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"24.1\", \"lessThan\": \"24.1R2-EVO\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"23.2R1-EVO\", \"versionType\": \"semver\"}], \"defaultStatus\": \"unaffected\"}], \"exploits\": [{\"lang\": \"en\", \"value\": \"Juniper SIRT is not aware of any malicious exploitation of this vulnerability.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"Juniper SIRT is not aware of any malicious exploitation of this vulnerability.\", \"base64\": false}]}], \"solutions\": [{\"lang\": \"en\", \"value\": \"The following software releases have been updated to resolve this specific issue:\\nJunos OS:\\u00a023.2R2, 23.4R1-S2, 23.4R2, 24.1R2, 24.2R1, and all subsequent releases.\\n\\n\\n Junos OS Evolved:\\u00a023.2R2-EVO, 23.4R1-S2-EVO, 23.4R2-EVO, 24.1R2-EVO, 24.2R1-EVO,\\u00a0and all subsequent releases.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"The following software releases have been updated to resolve this specific issue:\u003cbr\u003eJunos OS:\u0026nbsp;23.2R2, 23.4R1-S2, 23.4R2, 24.1R2, 24.2R1\u003cspan style=\\\"background-color: rgb(255, 255, 255);\\\"\u003e, and all subsequent releases.\u003c/span\u003e\\n\\n\u003cbr\u003e Junos OS Evolved:\u0026nbsp;23.2R2-EVO, 23.4R1-S2-EVO, 23.4R2-EVO, 24.1R2-EVO, 24.2R1-EVO,\u0026nbsp;\u003cspan style=\\\"background-color: rgb(255, 255, 255);\\\"\u003eand all subsequent releases.\u003c/span\u003e\\n\\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\", \"base64\": false}]}], \"datePublic\": \"2026-01-14T17:00:00.000Z\", \"references\": [{\"url\": \"https://supportportal.juniper.net/JSA106008\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://kb.juniper.net/JSA106008\", \"tags\": [\"vendor-advisory\"]}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"There are no known workarounds for this issue.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"There are no known workarounds for this issue.\", \"base64\": false}]}], \"x_generator\": {\"engine\": \"Vulnogram 0.1.0-dev\"}, \"descriptions\": [{\"lang\": \"en\", \"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.\\u00a0Continued 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 \u0027show task memory detail\u0027 command. For example:\\n\\nuser@junos\u003e show task memory detail | match ted-infra\\n\\u00a0 TED-INFRA-COOKIE  \\u00a0 \\u00a0 \\u00a0 \\u00a0 \\u00a0  25  \\u00a0  1072  \\u00a0 \\u00a0  28  \\u00a0  1184  \\u00a0 \\u00a0  229\\n\\n\\n\\nuser@junos\u003e \\n\\nshow task memory detail | match ted-infra\\n\\u00a0 TED-INFRA-COOKIE  \\u00a0 \\u00a0 \\u00a0 \\u00a0 \\u00a0  31  \\u00a0  1360  \\u00a0 \\u00a0  34  \\u00a0  1472  \\u00a0 \\u00a0  307\\n\\nThis issue affects:\\n\\nJunos OS:\\u00a0\\n\\n  *  from 23.2 before 23.2R2,\\u00a0\\n  *  from 23.4 before 23.4R1-S2, 23.4R2,\\u00a0\\n  *  from 24.1 before 24.1R2;\\u00a0\\n\\n\\nJunos OS Evolved:\\u00a0\\n\\n  *  from 23.2 before 23.2R2-EVO,\\u00a0\\n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO,\\u00a0\\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.\", \"supportingMedia\": [{\"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.\u0026nbsp;Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition.\u003cbr\u003e\u003cbr\u003eMemory usage can be monitored through the use of the \u0027show task memory detail\u0027 command. For example:\u003cbr\u003e\u003cbr\u003e\u003ctt\u003euser@junos\u0026gt; show task memory detail | match ted-infra\u003cbr\u003e\u0026nbsp; TED-INFRA-COOKIE  \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;  25  \u0026nbsp;  1072  \u0026nbsp; \u0026nbsp;  28  \u0026nbsp;  1184  \u0026nbsp; \u0026nbsp;  229\u003cbr\u003e\u003c/tt\u003e\u003cbr\u003e\\n\\n\u003ctt\u003euser@junos\u0026gt; \\n\\nshow task memory detail | match ted-infra\u003cbr\u003e\u0026nbsp; TED-INFRA-COOKIE  \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;  \u003cb\u003e\u003cspan style=\\\"background-color: rgb(239, 250, 102);\\\"\u003e31\u003c/span\u003e\u003c/b\u003e  \u0026nbsp;  \u003cb\u003e\u003cspan style=\\\"background-color: rgb(239, 250, 102);\\\"\u003e1360\u003c/span\u003e\u003c/b\u003e  \u0026nbsp; \u0026nbsp;  34  \u0026nbsp;  1472  \u0026nbsp; \u0026nbsp;  307\u003c/tt\u003e\u003cbr\u003e\u003cbr\u003e\u003cp\u003eThis issue affects:\u003c/p\u003e\u003cp\u003eJunos OS:\u0026nbsp;\u003c/p\u003e\u003cul\u003e\u003cli\u003efrom 23.2 before 23.2R2,\u0026nbsp;\u003c/li\u003e\u003cli\u003efrom 23.4 before 23.4R1-S2, 23.4R2,\u0026nbsp;\u003c/li\u003e\u003cli\u003efrom 24.1 before 24.1R2;\u0026nbsp;\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eJunos OS Evolved:\u0026nbsp;\u003c/p\u003e\u003cul\u003e\u003cli\u003efrom 23.2 before 23.2R2-EVO,\u0026nbsp;\u003c/li\u003e\u003cli\u003efrom 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO,\u0026nbsp;\u003c/li\u003e\u003cli\u003efrom 24.1 before 24.1R2-EVO.\u003c/li\u003e\u003c/ul\u003eThis issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO.\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-401\", \"description\": \"CWE-401 Missing Release of Memory after Effective Lifetime\"}]}], \"configurations\": [{\"lang\": \"en\", \"value\": \"This issue affects systems with IS-IS configured. For example:\\n\\n[protocols isis interface lo.0 ...]\\n\\n\\n[protocols isis interface \u003cinterface\u003e ...]\\n[interfaces \u003cinterface\u003e unit \u003cn\u003e family iso]\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"This issue affects systems with IS-IS configured. For example:\u003cbr\u003e\u003cbr\u003e\u003ctt\u003e[protocols isis interface lo.0 ...]\u003cbr\u003e\\n\\n[protocols isis interface \u0026lt;interface\u0026gt; ...]\u003cbr\u003e[interfaces \u0026lt;interface\u0026gt; unit \u0026lt;n\u0026gt; family iso]\u003c/tt\u003e\", \"base64\": false}]}], \"providerMetadata\": {\"orgId\": \"8cbe9d5a-a066-4c94-8978-4b15efeae968\", \"shortName\": \"juniper\", \"dateUpdated\": \"2026-01-15T20:22:44.674Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-21909\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-01-15T20:52:42.400Z\", \"dateReserved\": \"2026-01-05T17:32:48.710Z\", \"assignerOrgId\": \"8cbe9d5a-a066-4c94-8978-4b15efeae968\", \"datePublished\": \"2026-01-15T20:22:44.674Z\", \"assignerShortName\": \"juniper\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.