CVE-2026-33797

Estado: ModificadaAlta (7.1)—

An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).

An attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:

This issue does not affect Junos OS versions before 25.2R1.

This issue does not affect Junos OS Evolved versions before 25.2R1-EVO.

eBGP and iBGP are affected. IPv4 and IPv6 are affected.

Detalles técnicos trazas, registros y código del informe original

  *  25.2 versions before 25.2R2

This issue affects Junos OS Evolved: 
  *  25.2-EVO versions before 25.2R2-EVO

CVSS

Versión: 4.0
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
Puntuación base: 7.1

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.27%
Percentil entre todas las CVEs puntuadas: 17
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement60 %
Impacto principalT1499 Endpoint Denial of Serviceimpact55 %

Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Vulnerability Scanning Threat Intelligence Program Privileged Account Management Network Segmentation Filter Network Traffic Disable or Remove Feature or Program

Tecnologías afectadas (2)

Juniper — Junos Juniper — Junos OS Evolved

CWE

CWE-20

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-33797",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-33797",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-04-13T17:40:25.675431Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "sirt@juniper.net",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 7.4,
          "attackVector": "ADJACENT_NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 4,
        "exploitabilityScore": 2.8
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "sirt@juniper.net",
        "cvssData": {
          "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/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",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "GREEN",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "LOW",
          "vulnAvailabilityImpact": "HIGH",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "MODERATE",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
        }
      }
    ]
  },
  "affected": [
    {
      "source": "sirt@juniper.net",
      "affectedData": [
        {
          "vendor": "Juniper Networks",
          "product": "Junos OS",
          "versions": [
            {
              "status": "affected",
              "version": "25.2",
              "lessThan": "25.2R2",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "25.2R1",
              "versionType": "semver"
            }
          ],
          "defaultStatus": "unaffected"
        },
        {
          "vendor": "Juniper Networks",
          "modules": [
            "bgp"
          ],
          "product": "Junos OS Evolved",
          "versions": [
            {
              "status": "affected",
              "version": "25.2",
              "lessThan": "25.2R2-EVO",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "25.2R1-EVO",
              "versionType": "semver"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-04-09T22:16:29.547",
  "references": [
    {
      "url": "https://kb.juniper.net/JSA107850",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "sirt@juniper.net"
    },
    {
      "url": "https://supportportal.juniper.net/JSA107850",
      "source": "sirt@juniper.net"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "sirt@juniper.net",
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).\n\nAn attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:\n\n  *  25.2 versions before 25.2R2\n\n\nThis issue does not affect Junos OS versions before 25.2R1.\n\nThis issue affects Junos OS Evolved: \n  *  25.2-EVO versions before 25.2R2-EVO\n\n\nThis issue does not affect Junos OS Evolved versions before 25.2R1-EVO.\n\neBGP and iBGP are affected.\nIPv4 and IPv6 are affected."
    }
  ],
  "lastModified": "2026-06-17T10:38:07.160",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:juniper:junos:25.2:-:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "1B7572BB-9C77-4214-9C5F-CC83C7B93E37"
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:25.2:r1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "CAADBF98-38BE-40E2-AF1B-9077DCED0809"
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:25.2:r1-s1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "558F0A4C-0C72-4BF1-B2DE-C0D3BFD54BCD"
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:25.2:r1-s2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "127FE528-AB27-4B18-AF3B-1BE7C0AEEE20"
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos_os_evolved:25.2:-:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DAF96553-DB70-4DFA-8658-306A7477DD06"
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos_os_evolved:25.2:r1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "83C415EF-E87B-4259-A836-59B3A9C3914B"
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "AFD32E67-9D8D-437D-96BC-CA97A1F686BA"
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0E5D9967-1B53-427B-9B23-77DC399F3D71"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "sirt@juniper.net"
}