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

FKIE_CVE-2026-21916

Vulnerability from fkie_nvd - Published: 2026-04-09 22:16 - Updated: 2026-06-17 10:19
Summary
A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system. When after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root. This issue affects Junos OS: * all versions before 23.2R2-S7, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S3, * 24.4 versions before 24.4R2-S2, * 25.2 versions before 25.2R2. This issue does not affect versions 25.4R1 or later.
References
sirt@juniper.nethttps://kb.juniper.net/JSA107807Mitigation, Vendor Advisory
Impacted products

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Junos OS",
          "vendor": "Juniper Networks",
          "versions": [
            {
              "lessThan": "23.2R2-S7",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "23.4R2-S6",
              "status": "affected",
              "version": "23.4",
              "versionType": "semver"
            },
            {
              "lessThan": "24.2R2-S3",
              "status": "affected",
              "version": "24.2",
              "versionType": "semver"
            },
            {
              "lessThan": "24.4R2-S2",
              "status": "affected",
              "version": "24.4",
              "versionType": "semver"
            },
            {
              "lessThan": "25.2R2",
              "status": "affected",
              "version": "25.2",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "25.4R1"
            }
          ]
        }
      ],
      "source": "sirt@juniper.net"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "3D14745F-3090-483F-9DB4-C424FA09BD21",
              "versionEndExcluding": "23.2",
              "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:23.2:r2:*:*:*:*:*:*",
              "matchCriteriaId": "1ADA814B-EF98-45B1-AF7A-0C89688F7CA5",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.2:r2-s1:*:*:*:*:*:*",
              "matchCriteriaId": "A6FB32DF-D062-4FB9-8777-452978BEC7B7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:*",
              "matchCriteriaId": "B3B6C811-5C10-4486-849D-5559B592350A",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.2:r2-s3:*:*:*:*:*:*",
              "matchCriteriaId": "078D61B9-A228-453C-9D20-6F9C6B20637F",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.2:r2-s4:*:*:*:*:*:*",
              "matchCriteriaId": "F1F136A0-021D-43FE-BDD3-AD7201F7FC03",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.2:r2-s5:*:*:*:*:*:*",
              "matchCriteriaId": "37147BC9-9ED8-48AE-906A-614AD8600962",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.2:r2-s6:*:*:*:*:*:*",
              "matchCriteriaId": "7897729C-4128-49E9-B4A1-25353BC4DBB2",
              "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:r1-s2:*:*:*:*:*:*",
              "matchCriteriaId": "CB2D1FCE-8019-4CE1-BA45-D62F91AF7B51",
              "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:23.4:r2-s1:*:*:*:*:*:*",
              "matchCriteriaId": "166BFDB3-1945-4949-BC2B-E18442FF2E4D",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:*",
              "matchCriteriaId": "5923610F-878C-48CA-8B5D-9C609E4DD4DB",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:*",
              "matchCriteriaId": "A7C207E3-0252-4192-8E8C-E2ED2831B4F4",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.4:r2-s4:*:*:*:*:*:*",
              "matchCriteriaId": "E6974492-FE69-4340-8881-61C3329C1545",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:23.4:r2-s5:*:*:*:*:*:*",
              "matchCriteriaId": "279E59FE-96DF-4E1D-A3A2-61D180F04533",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:*",
              "matchCriteriaId": "89524D6D-0B22-4952-AD8E-8072C5A05D5C",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:*",
              "matchCriteriaId": "AD69A194-1B03-44EA-8092-79BD10C6F729",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:*",
              "matchCriteriaId": "8463ADB4-B8A7-4D63-97A9-232ED713A21C",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:*",
              "matchCriteriaId": "FE68337F-106E-4317-A5B6-292B0159F577",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.2:r2:*:*:*:*:*:*",
              "matchCriteriaId": "266B520A-482A-43F7-90F8-B9D64D30034F",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.2:r2-s1:*:*:*:*:*:*",
              "matchCriteriaId": "AC78BC9E-5DA7-4E42-9923-B49A0B7F3564",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.2:r2-s2:*:*:*:*:*:*",
              "matchCriteriaId": "DD99F1B0-82B0-4CD3-8C8F-C0FFF44A8B90",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.4:-:*:*:*:*:*:*",
              "matchCriteriaId": "C452BDCB-34E3-42D3-8909-2312356EB70A",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.4:r1:*:*:*:*:*:*",
              "matchCriteriaId": "2B8158F2-2028-40E9-955F-CFD581A32F60",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.4:r1-s2:*:*:*:*:*:*",
              "matchCriteriaId": "1A7233A1-EC7A-4458-9AE1-835480A03A21",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.4:r1-s3:*:*:*:*:*:*",
              "matchCriteriaId": "D74087E2-5CAA-4085-8408-EB70EC1D5D91",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.4:r2:*:*:*:*:*:*",
              "matchCriteriaId": "0EEF1798-F3C2-4645-96E7-1E82368B184D",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:24.4:r2-s1:*:*:*:*:*:*",
              "matchCriteriaId": "C8BB5EE1-04C7-4DF3-807A-06005ECFEEE5",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:25.2:-:*:*:*:*:*:*",
              "matchCriteriaId": "1B7572BB-9C77-4214-9C5F-CC83C7B93E37",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:25.2:r1:*:*:*:*:*:*",
              "matchCriteriaId": "CAADBF98-38BE-40E2-AF1B-9077DCED0809",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:25.2:r1-s1:*:*:*:*:*:*",
              "matchCriteriaId": "558F0A4C-0C72-4BF1-B2DE-C0D3BFD54BCD",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:juniper:junos:25.2:r1-s2:*:*:*:*:*:*",
              "matchCriteriaId": "127FE528-AB27-4B18-AF3B-1BE7C0AEEE20",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system.\n\nWhen after a user has performed a specific \u0027file link ...\u0027 CLI operation, another user commits (unrelated configuration changes), the first user can login as root.\n\nThis issue affects Junos OS:\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S6,\n  *  24.2 versions before 24.2R2-S3,\n  *  24.4 versions before 24.4R2-S2,\n  *  25.2 versions before 25.2R2.\n\n\nThis issue does not affect versions 25.4R1 or later."
    }
  ],
  "id": "CVE-2026-21916",
  "lastModified": "2026-06-17T10:19:09.340",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.3,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.3,
        "impactScore": 5.9,
        "source": "sirt@juniper.net",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "YES",
          "Recovery": "USER",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "LOCAL",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "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": "LOW",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "PASSIVE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/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:U/V:X/RE:M/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "MODERATE"
        },
        "source": "sirt@juniper.net",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-21916",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-04-10T03:56:11.604149Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-04-09T22:16:24.953",
  "references": [
    {
      "source": "sirt@juniper.net",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://kb.juniper.net/JSA107807"
    }
  ],
  "sourceIdentifier": "sirt@juniper.net",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-61"
        }
      ],
      "source": "sirt@juniper.net",
      "type": "Secondary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

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.


Loading…