FKIE_CVE-2026-57031

Vulnerability from fkie_nvd - Published: 2026-07-09 22:17 - Updated: 2026-07-09 22:17
Severity
4.7 (Medium) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Summary
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on MX Series allows adjacent subscribers to bypass configured firewall filters. On MX Series devices with MPC10/11, LC4800/9600, and MX304 with subscribers configured on static interfaces, ingress firewall filters are not enforced, so that neither protocol level nor upstream bandwidth limitation are in effect.  This issue affects Junos OS on MX with MPC10/11, LC4800/9600/4802, and MX304: * 23.2 versions from 23.2R2-S1 before 23.2R2-S7, * 23.4 versions from 23.4R2 before 23.4R2-S7, * 24.2 versions before 24.2R2-S3, * 24.4 versions before 24.4R2-S2, * 25.2 versions before 25.2R2.
References
sirt@juniper.nethttps://supportportal.juniper.net/JSA110091
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "modules": [
            "MPC10",
            "MPC11",
            "LC4800",
            "LC9600",
            "MX304-LMIC16"
          ],
          "platforms": [
            "MX Series"
          ],
          "product": "Junos OS",
          "vendor": "Juniper Networks",
          "versions": [
            {
              "lessThan": "23.2R2-S7",
              "status": "affected",
              "version": "23.2R2-S1",
              "versionType": "custom"
            },
            {
              "lessThan": "23.4R2-S7",
              "status": "affected",
              "version": "23.4R2",
              "versionType": "custom"
            },
            {
              "lessThan": "24.2R2-S3",
              "status": "affected",
              "version": "24.2",
              "versionType": "custom"
            },
            {
              "lessThan": "24.4R2-S2",
              "status": "affected",
              "version": "24.4",
              "versionType": "custom"
            },
            {
              "lessThan": "25.2R2",
              "status": "affected",
              "version": "25.2",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "sirt@juniper.net"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on MX Series allows adjacent subscribers to bypass configured firewall filters.\n\nOn MX Series devices with\u00a0MPC10/11, LC4800/9600, and MX304 with\u00a0subscribers configured on static interfaces, ingress firewall filters are not enforced, so that neither protocol level nor upstream bandwidth limitation are in effect.\u00a0\n\n\nThis issue affects Junos OS on MX with\u00a0MPC10/11, LC4800/9600/4802, and MX304:\n\n\n  *  23.2 versions from 23.2R2-S1 before 23.2R2-S7,\n  *  23.4 versions from 23.4R2 before 23.4R2-S7,\n  *  24.2 versions before 24.2R2-S3,\n  *  24.4 versions before 24.4R2-S2,\n  *  25.2 versions before 25.2R2."
    }
  ],
  "id": "CVE-2026-57031",
  "lastModified": "2026-07-09T22:17:08.827",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4,
        "source": "sirt@juniper.net",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "YES",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "ADJACENT",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "LOW",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/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:X/V:X/RE:M/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "MODERATE"
        },
        "source": "sirt@juniper.net",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-09T22:17:08.827",
  "references": [
    {
      "source": "sirt@juniper.net",
      "url": "https://supportportal.juniper.net/JSA110091"
    }
  ],
  "sourceIdentifier": "sirt@juniper.net",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-754"
        }
      ],
      "source": "sirt@juniper.net",
      "type": "Primary"
    }
  ]
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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