Gitea trusted workflow cancellation by unapproved fork runs

{
  "id": "d632a4f4e355aff580ecac2af8f7de13b5655ff5d29d82debd8198fe9f0139cb",
  "url": "https://osv.dev/vulnerability/CVE-2026-103670",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Gitea trusted workflow cancellation by unapproved fork runs",
    "summary": "When a Gitea Actions run was inserted, older runs in the same workflow-level concurrency group were cancelled without checking whether the new run still needed approval. Because fork pull request runs are inserted under the base repository, a user who can open a pull request from a fork could cancel trusted in-progress runs that share a concurrency group with `cancel-in-progress` enabled, without approval and without running any code. On self-hosted runners this can interrupt deployments and leave partial state behind.",
    "evidence": "osv:CVE-2026-103670",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-103670",
      "aliases": [
        "BIT-gitea-2026-103670",
        "CVE-2026-103670",
        "GHSA-4j4g-m7mr-hp5j"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/go-gitea/gitea",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "15b8a5805adf57c5189602008d38cccfd3c795e0"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:gitea:gitea:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "28.0.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "15b8a5805adf57c5189602008d38cccfd3c795e0"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v28.0.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v29.0.0-dev",
            "v1.28.0-dev",
            "v1.27.0-dev",
            "v1.26.0-dev",
            "v1.25.0-dev",
            "v1.24.0-dev",
            "v1.22.0-rc1",
            "v1.23.0-dev",
            "v1.22.0-rc0",
            "v1.21.0-rc0",
            "v1.22.0-dev",
            "v1.20.0-rc0",
            "v1.21.0-dev",
            "v1.20.0-dev",
            "v1.19.0-rc0",
            "v1.18.0-rc0",
            "v1.19.0-dev",
            "v1.18.0-dev",
            "v1.17.0-dev",
            "v1.16.0-rc1",
            "v1.15.0-rc1",
            "v1.16.0-dev",
            "v1.15.0-dev",
            "v1.14.0-dev",
            "v1.13.0-dev",
            "v1.12.0-dev",
            "v1.10.5",
            "v1.11.0-rc1",
            "v1.10.0-rc1",
            "v1.11.0-dev",
            "v1.9.0-rc1",
            "v1.10.0-dev",
            "v1.9.0-dev",
            "v1.7.0-dev",
            "v1.6.0-rc1",
            "v1.6.0-dev",
            "v1.5.0-rc1",
            "v1.5.0-dev",
            "v1.1.0",
            "v1.0.0",
            "v0.9.99"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-103670.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.090642010Z",
      "provider": "osv",
      "references": [
        "https://blog.gitea.com/release-of-28.0.0/",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103670.json",
        "https://github.com/go-gitea/gitea/releases/tag/v28.0.0",
        "https://github.com/go-gitea/gitea/security/advisories/GHSA-4j4g-m7mr-hp5j",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-103670",
        "https://github.com/go-gitea/gitea/pull/39399"
      ],
      "provider_metadata": {
        "cna_assigner": "Gitea",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103670.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-103670",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489693,
  "published_at": "2026-10-06T19:23:40.05+00:00"
}