CVE-2026-9132 (GCVE-0-2026-9132)

Vulnerability from cvelistv5 – Published: 2026-06-30 20:23 – Updated: 2026-07-01 15:37
VLAI
Title
Missing authorization vulnerability in GitHub Enterprise Server allowed disclosure of private repository contents via the Copilot pull request diff summary endpoint
Summary
A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program.
Severity
6 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
Assigner
References
Impacted products
Vendor Product Version
GitHub Enterprise Server Affected: 3.17.0 , ≤ 3.17.16 (semver)
Affected: 3.18.0 , ≤ 3.18.10 (semver)
Affected: 3.19.0 , ≤ 3.19.7 (semver)
Affected: 3.20.0 , ≤ 3.20.3 (semver)
Create a notification for this product.
Credits
Seokchan Yoon
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-9132",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-01T15:37:41.106015Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-01T15:37:50.129Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Enterprise Server",
          "vendor": "GitHub",
          "versions": [
            {
              "changes": [
                {
                  "at": "3.17.17",
                  "status": "unaffected"
                }
              ],
              "lessThanOrEqual": "3.17.16",
              "status": "affected",
              "version": "3.17.0",
              "versionType": "semver"
            },
            {
              "changes": [
                {
                  "at": "3.18.11",
                  "status": "unaffected"
                }
              ],
              "lessThanOrEqual": "3.18.10",
              "status": "affected",
              "version": "3.18.0",
              "versionType": "semver"
            },
            {
              "changes": [
                {
                  "at": "3.19.8",
                  "status": "unaffected"
                }
              ],
              "lessThanOrEqual": "3.19.7",
              "status": "affected",
              "version": "3.19.0",
              "versionType": "semver"
            },
            {
              "changes": [
                {
                  "at": "3.20.4",
                  "status": "unaffected"
                }
              ],
              "lessThanOrEqual": "3.20.3",
              "status": "affected",
              "version": "3.20.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Seokchan Yoon"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The\u003cbr\u003e   Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view\u003cbr\u003e   the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all\u003cbr\u003e   versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program."
            }
          ],
          "value": "A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The\n   Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view\n   the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all\n   versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-1",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-862",
              "description": "CWE-862 Missing Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-30T20:23:37.445Z",
        "orgId": "82327ea3-741d-41e4-88f8-2cf9e791e760",
        "shortName": "GitHub_P"
      },
      "references": [
        {
          "url": "https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17-features"
        },
        {
          "url": "https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.11-features"
        },
        {
          "url": "https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.8-features"
        },
        {
          "url": "https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.4-features"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Missing authorization vulnerability in GitHub Enterprise Server allowed disclosure of private repository contents via the Copilot pull request diff summary endpoint",
      "x_generator": {
        "engine": "Vulnogram 1.0.2"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "82327ea3-741d-41e4-88f8-2cf9e791e760",
    "assignerShortName": "GitHub_P",
    "cveId": "CVE-2026-9132",
    "datePublished": "2026-06-30T20:23:37.445Z",
    "dateReserved": "2026-05-20T18:18:07.930Z",
    "dateUpdated": "2026-07-01T15:37:50.129Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-9132",
      "date": "2026-07-01",
      "epss": "0.00284",
      "percentile": "0.20208"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-9132\",\"sourceIdentifier\":\"product-cna@github.com\",\"published\":\"2026-06-30T21:16:30.960\",\"lastModified\":\"2026-07-01T19:57:18.920\",\"vulnStatus\":\"Undergoing Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The\\n   Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view\\n   the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all\\n   versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program.\"}],\"affected\":[{\"source\":\"product-cna@github.com\",\"affectedData\":[{\"vendor\":\"GitHub\",\"product\":\"Enterprise Server\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"3.17.0\",\"lessThanOrEqual\":\"3.17.16\",\"versionType\":\"semver\",\"status\":\"affected\",\"changes\":[{\"at\":\"3.17.17\",\"status\":\"unaffected\"}]},{\"version\":\"3.18.0\",\"lessThanOrEqual\":\"3.18.10\",\"versionType\":\"semver\",\"status\":\"affected\",\"changes\":[{\"at\":\"3.18.11\",\"status\":\"unaffected\"}]},{\"version\":\"3.19.0\",\"lessThanOrEqual\":\"3.19.7\",\"versionType\":\"semver\",\"status\":\"affected\",\"changes\":[{\"at\":\"3.19.8\",\"status\":\"unaffected\"}]},{\"version\":\"3.20.0\",\"lessThanOrEqual\":\"3.20.3\",\"versionType\":\"semver\",\"status\":\"affected\",\"changes\":[{\"at\":\"3.20.4\",\"status\":\"unaffected\"}]}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"product-cna@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/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\",\"baseScore\":6.0,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"PRESENT\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"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\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-01T15:37:41.106015Z\",\"id\":\"CVE-2026-9132\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"product-cna@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-862\"}]}],\"references\":[{\"url\":\"https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17-features\",\"source\":\"product-cna@github.com\"},{\"url\":\"https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.11-features\",\"source\":\"product-cna@github.com\"},{\"url\":\"https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.8-features\",\"source\":\"product-cna@github.com\"},{\"url\":\"https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.4-features\",\"source\":\"product-cna@github.com\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-9132\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-01T15:37:41.106015Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-01T15:37:47.228Z\"}}], \"cna\": {\"title\": \"Missing authorization vulnerability in GitHub Enterprise Server allowed disclosure of private repository contents via the Copilot pull request diff summary endpoint\", \"source\": {\"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Seokchan Yoon\"}], \"impacts\": [{\"capecId\": \"CAPEC-1\", \"descriptions\": [{\"lang\": \"en\", \"value\": \"CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs\"}]}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 6, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"LOW\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"HIGH\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"GitHub\", \"product\": \"Enterprise Server\", \"versions\": [{\"status\": \"affected\", \"changes\": [{\"at\": \"3.17.17\", \"status\": \"unaffected\"}], \"version\": \"3.17.0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"3.17.16\"}, {\"status\": \"affected\", \"changes\": [{\"at\": \"3.18.11\", \"status\": \"unaffected\"}], \"version\": \"3.18.0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"3.18.10\"}, {\"status\": \"affected\", \"changes\": [{\"at\": \"3.19.8\", \"status\": \"unaffected\"}], \"version\": \"3.19.0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"3.19.7\"}, {\"status\": \"affected\", \"changes\": [{\"at\": \"3.20.4\", \"status\": \"unaffected\"}], \"version\": \"3.20.0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"3.20.3\"}], \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17-features\"}, {\"url\": \"https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.11-features\"}, {\"url\": \"https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.8-features\"}, {\"url\": \"https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.4-features\"}], \"x_generator\": {\"engine\": \"Vulnogram 1.0.2\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The\\n   Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view\\n   the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all\\n   versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The\u003cbr\u003e   Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view\u003cbr\u003e   the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all\u003cbr\u003e   versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program.\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-862\", \"description\": \"CWE-862 Missing Authorization\"}]}], \"providerMetadata\": {\"orgId\": \"82327ea3-741d-41e4-88f8-2cf9e791e760\", \"shortName\": \"GitHub_P\", \"dateUpdated\": \"2026-06-30T20:23:37.445Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-9132\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-01T15:37:50.129Z\", \"dateReserved\": \"2026-05-20T18:18:07.930Z\", \"assignerOrgId\": \"82327ea3-741d-41e4-88f8-2cf9e791e760\", \"datePublished\": \"2026-06-30T20:23:37.445Z\", \"assignerShortName\": \"GitHub_P\"}",
      "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.