Vulnerability-Lookup

GHSA-QRJ7-4954-7P6V

Vulnerability from github – Published: 2026-02-18 21:31 – Updated: 2026-02-20 00:31

Details

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enable_auto_merge mutation for pull requests. This issue only affected repositories that allow forking as the attack relies on opening a pull request from an attacker-controlled fork into the target repository. Exploitation was only possible in specific scenarios. It required a clean pull request status and only applied to branches without branch protection rules enabled. This vulnerability affected GitHub Enterprise Server versions prior to 3.19.2, 3.18.5, and 3.17.11, and was fixed in versions 3.19.2, 3.18.5, and 3.17.11. This vulnerability was reported via the GitHub Bug Bounty program.

Severity ?

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

7.1 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:L/SI:H/SA:N

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-1999"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-18T21:16:24Z",
    "severity": "HIGH"
  },
  "details": "An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enable_auto_merge mutation for pull requests. This issue only affected repositories that allow forking as the attack relies on opening a pull request from an attacker-controlled fork into the target repository. Exploitation was only possible in specific scenarios. It required a clean pull request status and only applied to branches without branch protection rules enabled. This vulnerability affected GitHub Enterprise Server versions prior to 3.19.2, 3.18.5, and 3.17.11, and was fixed in versions 3.19.2, 3.18.5, and 3.17.11. This vulnerability was reported via the GitHub Bug Bounty program.",
  "id": "GHSA-qrj7-4954-7p6v",
  "modified": "2026-02-20T00:31:52Z",
  "published": "2026-02-18T21:31:23Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-1999"
    },
    {
      "type": "WEB",
      "url": "https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.11"
    },
    {
      "type": "WEB",
      "url": "https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.5"
    },
    {
      "type": "WEB",
      "url": "https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:L/SI:H/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-1999 (GCVE-0-2026-1999)

Vulnerability from cvelistv5 – Published: 2026-02-18 20:44 – Updated: 2026-02-19 14:32

Title

Incorrect Authorization vulnerability was identified in GitHub Enterprise Server that allowed unauthorized merging of pull requests

Summary

Severity ?

7.1 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:L/SI:H/SA:N

CWE

CWE-863 - Incorrect Authorization

Assigner

GitHub_P

References

URL

Tags

	https://docs.github.com/en/enterprise-server@3.17…	release-notes
	https://docs.github.com/en/enterprise-server@3.18…	release-notes
	https://docs.github.com/en/enterprise-server@3.19…	release-notes

Impacted products

	Vendor	Product	Version
	GitHub	Enterprise Server	Affected: 3.17.0 , < 3.17.11 (semver) Affected: 3.18.0 , < 3.18.5 (semver) Affected: 3.19.0 , < 3.19.2 (semver)

Credits

ahacker1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-1999",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-19T14:31:31.276186Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-02-19T14:32:12.248Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "product": "Enterprise Server",
          "vendor": "GitHub",
          "versions": [
            {
              "changes": [
                {
                  "at": "3.17.11",
                  "status": "unaffected"
                }
              ],
              "lessThan": "3.17.11",
              "status": "affected",
              "version": "3.17.0",
              "versionType": "semver"
            },
            {
              "changes": [
                {
                  "at": "3.18.5",
                  "status": "unaffected"
                }
              ],
              "lessThan": "3.18.5",
              "status": "affected",
              "version": "3.18.0",
              "versionType": "semver"
            },
            {
              "changes": [
                {
                  "at": "3.19.2",
                  "status": "unaffected"
                }
              ],
              "lessThan": "3.19.2",
              "status": "affected",
              "version": "3.19.0",
              "versionType": "semver"
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      ],
      "credits": [
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        }
      ],
      "impacts": [
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          "capecId": "CAPEC-233",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-233 Privilege Escalation"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:L/SI:H/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
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              "lang": "en",
              "value": "GENERAL"
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      "problemTypes": [
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      "providerMetadata": {
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        "orgId": "82327ea3-741d-41e4-88f8-2cf9e791e760",
        "shortName": "GitHub_P"
      },
      "references": [
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          "tags": [
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          "url": "https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.11"
        },
        {
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            "release-notes"
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          "url": "https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.5"
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          ],
          "url": "https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.2"
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      "source": {
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  "cveMetadata": {
    "assignerOrgId": "82327ea3-741d-41e4-88f8-2cf9e791e760",
    "assignerShortName": "GitHub_P",
    "cveId": "CVE-2026-1999",
    "datePublished": "2026-02-18T20:44:51.396Z",
    "dateReserved": "2026-02-05T17:14:39.098Z",
    "dateUpdated": "2026-02-19T14:32:12.248Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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.

Action not permitted

GHSA-QRJ7-4954-7P6V

CVE-2026-1999 (GCVE-0-2026-1999)

Tags

Sightings

Nomenclature