Vulnerability-Lookup

GHSA-3X3P-RPWC-H9WF

Vulnerability from github – Published: 2026-08-05 21:31 – Updated: 2026-08-05 21:31

Details

A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause excessive CPU consumption and exhaust the pool of request-handling worker processes by sending a crafted form-encoded HTTP POST request containing deeply nested parameters. Because request parameters were parsed before routing and authentication, any POST endpoint could be used to trigger the condition, which could render the instance unresponsive. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.3, 3.19.7, 3.18.10, and 3.17.16.

Severity

6.6 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-15996"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-05T21:16:57Z",
    "severity": "MODERATE"
  },
  "details": "A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause excessive CPU consumption and exhaust the pool of request-handling worker processes by sending a crafted form-encoded HTTP POST request containing deeply nested parameters. Because request parameters were parsed before routing and authentication, any POST endpoint could be used to trigger the condition, which could render the instance unresponsive. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.3, 3.19.7, 3.18.10, and 3.17.16.",
  "id": "GHSA-3x3p-rpwc-h9wf",
  "modified": "2026-08-05T21:31:39Z",
  "published": "2026-08-05T21:31:39Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-15996"
    },
    {
      "type": "WEB",
      "url": "https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.16"
    },
    {
      "type": "WEB",
      "url": "https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.10"
    },
    {
      "type": "WEB",
      "url": "https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.7"
    },
    {
      "type": "WEB",
      "url": "https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/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-2026-15996 (GCVE-0-2026-15996)

Vulnerability from cvelistv5 – Published: 2026-08-05 20:12 – Updated: 2026-08-06 13:48

Title

Denial of service vulnerability in GitHub Enterprise Server allowed unauthenticated service disruption via deeply nested request parameters

Summary

Severity

6.6 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-674 - Uncontrolled Recursion

Assigner

GitHub_P

References

4 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
https://docs.github.com/en/enterprise-server@3.20…	release-notes

Impacted products

1 product

Vendor	Product	Version
GitHub	Enterprise Server	Affected: 3.17.0 , ≤ 3.17.15 (semver) Affected: 3.18.0 , ≤ 3.18.9 (semver) Affected: 3.19.0 , ≤ 3.19.6 (semver) Affected: 3.20.0 , ≤ 3.20.2 (semver)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-15996",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-06T13:48:48.535295Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-06T13:48:59.999Z",
          "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": "3.17.16",
                  "status": "unaffected"
                }
              ],
              "lessThanOrEqual": "3.17.15",
              "status": "affected",
              "version": "3.17.0",
              "versionType": "semver"
            },
            {
              "changes": [
                {
                  "at": "3.18.10",
                  "status": "unaffected"
                }
              ],
              "lessThanOrEqual": "3.18.9",
              "status": "affected",
              "version": "3.18.0",
              "versionType": "semver"
            },
            {
              "changes": [
                {
                  "at": "3.19.7",
                  "status": "unaffected"
                }
              ],
              "lessThanOrEqual": "3.19.6",
              "status": "affected",
              "version": "3.19.0",
              "versionType": "semver"
            },
            {
              "changes": [
                {
                  "at": "3.20.3",
                  "status": "unaffected"
                }
              ],
              "lessThanOrEqual": "3.20.2",
              "status": "affected",
              "version": "3.20.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause excessive CPU consumption and exhaust the pool of request-handling worker processes by sending a crafted form-encoded HTTP POST request containing deeply nested parameters. Because request parameters were parsed before routing and authentication, any POST endpoint could be used to trigger the condition, which could render the instance unresponsive. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.3, 3.19.7, 3.18.10, and 3.17.16.\u003cbr\u003e\u003cbr\u003e"
            }
          ],
          "value": "A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause excessive CPU consumption and exhaust the pool of request-handling worker processes by sending a crafted form-encoded HTTP POST request containing deeply nested parameters. Because request parameters were parsed before routing and authentication, any POST endpoint could be used to trigger the condition, which could render the instance unresponsive. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.3, 3.19.7, 3.18.10, and 3.17.16."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-130",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-130 Excessive Allocation"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.6,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "UNREPORTED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-674",
              "description": "CWE-674 Uncontrolled Recursion",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T20:12:57.955Z",
        "orgId": "82327ea3-741d-41e4-88f8-2cf9e791e760",
        "shortName": "GitHub_P"
      },
      "references": [
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.16"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.10"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.7"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.3"
        }
      ],
      "source": {
        "discovery": "INTERNAL"
      },
      "title": "Denial of service vulnerability in GitHub Enterprise Server allowed unauthenticated service disruption via deeply nested request parameters",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "82327ea3-741d-41e4-88f8-2cf9e791e760",
    "assignerShortName": "GitHub_P",
    "cveId": "CVE-2026-15996",
    "datePublished": "2026-08-05T20:12:57.955Z",
    "dateReserved": "2026-07-16T21:29:33.097Z",
    "dateUpdated": "2026-08-06T13:48:59.999Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

GHSA-3X3P-RPWC-H9WF

CVE-2026-15996 (GCVE-0-2026-15996)

Tags

Sightings

Nomenclature