FKIE_CVE-2026-5845

Vulnerability from fkie_nvd - Published: 2026-04-21 23:16 - Updated: 2026-04-22 21:23
Severity ?
7.2 (High) - CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N
Summary
An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterprise Server allows an authenticated attacker to access private repositories outside the intended installation scope, which can include write operations, via an authorization fallback that treated a revoked/deleted installation as a global installation context, which could be chained with token revocation timing and SSH push attribution to obtain and reuse a victim-scoped token. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.
References
product-cna@github.comhttps://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.26
product-cna@github.comhttps://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.21
product-cna@github.comhttps://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.17
product-cna@github.comhttps://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.14
product-cna@github.comhttps://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.8
product-cna@github.comhttps://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.5
product-cna@github.comhttps://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.1
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterprise Server allows an authenticated attacker to access private repositories outside the intended installation scope, which can include write operations, via an authorization fallback that treated a revoked/deleted installation as a global installation context, which could be chained with token revocation timing and SSH push attribution to obtain and reuse a victim-scoped token. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program."
    }
  ],
  "id": "CVE-2026-5845",
  "lastModified": "2026-04-22T21:23:52.620",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "LOCAL",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.2,
          "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": "NONE",
          "subConfidentialityImpact": "LOW",
          "subIntegrityImpact": "LOW",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:L/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:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "product-cna@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-04-21T23:16:22.473",
  "references": [
    {
      "source": "product-cna@github.com",
      "url": "https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.26"
    },
    {
      "source": "product-cna@github.com",
      "url": "https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.21"
    },
    {
      "source": "product-cna@github.com",
      "url": "https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.17"
    },
    {
      "source": "product-cna@github.com",
      "url": "https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.14"
    },
    {
      "source": "product-cna@github.com",
      "url": "https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.8"
    },
    {
      "source": "product-cna@github.com",
      "url": "https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.5"
    },
    {
      "source": "product-cna@github.com",
      "url": "https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.1"
    }
  ],
  "sourceIdentifier": "product-cna@github.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-639"
        }
      ],
      "source": "product-cna@github.com",
      "type": "Secondary"
    }
  ]
}


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  • 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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