Reliance on Reverse DNS Resolution for a Security-Critical Action in GitLab

{
  "id": "6c705fa94a81dc9c34cd34b08841d292db1981d5a4f81d58941d4b4f4424c5d4",
  "url": "https://osv.dev/vulnerability/CVE-2026-12635",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Reliance on Reverse DNS Resolution for a Security-Critical Action in GitLab",
    "summary": "GitLab has remediated an issue in GitLab CE/EE affecting all versions from 8.3 before 18.11.6, 19.0 before 19.0.3, and 19.1 before 19.1.1 that under certain conditions could have allowed an authenticated user with maintainer-role permissions to make requests to internal network resources through mirror synchronization due to improper URL validation.",
    "evidence": "osv:CVE-2026-12635",
    "products": [],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-12635",
      "aliases": [
        "BIT-gitlab-2026-12635",
        "CVE-2026-12635"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://gitlab.com/gitlab-org/gitlab",
              "type": "GIT",
              "events": [
                {
                  "introduced": "a810cc509e54b71aff30dfb9ba52ea4aea587c32"
                },
                {
                  "fixed": "0626dbe45d0ea9a431f494135ee4636d149eb523"
                },
                {
                  "introduced": "f07e3c5b3c8128be5db112e5b2b618fe31ea1b35"
                },
                {
                  "fixed": "e1892478cfb7980c694d13e0e5e15e129aa3d908"
                },
                {
                  "introduced": "67581074a0aab1f53cdafe7eead5f5d07f3afec8"
                },
                {
                  "last_affected": "67581074a0aab1f53cdafe7eead5f5d07f3afec8"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "8.3.0"
                      },
                      {
                        "fixed": "18.11.6"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "19.0.0"
                      },
                      {
                        "fixed": "19.0.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:gitlab:gitlab:19.1.0:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "19.1.0"
                      },
                      {
                        "last_affected": "19.1.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "19.1.0",
            "v19.1.0-ee",
            "v19.0.0-ee"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-12635.json"
          }
        }
      ],
      "modified": "2026-10-30T10:30:18.265819274Z",
      "provider": "osv",
      "references": [
        "https://docs.gitlab.com/releases/patches/patch-release-gitlab-19-1-1-released/",
        "https://gitlab.com/gitlab-org/gitlab/-/work_items/594321",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12635.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-12635"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-350"
        ],
        "cna_assigner": "GitLab",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "8.3"
                  },
                  {
                    "fixed": "18.11.6"
                  },
                  {
                    "introduced": "19.0"
                  },
                  {
                    "fixed": "19.0.3"
                  },
                  {
                    "introduced": "19.1"
                  },
                  {
                    "fixed": "19.1.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "8.3"
                  },
                  {
                    "fixed": "18.11.6"
                  },
                  {
                    "introduced": "19.0"
                  },
                  {
                    "fixed": "19.0.3"
                  },
                  {
                    "introduced": "19.1"
                  },
                  {
                    "fixed": "19.1.1"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12635.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-12635",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 501179,
  "published_at": "2026-06-25T04:33:34.156+00:00"
}