Composer: Path traversal in package bin field lets dependencies chmod arbitrary host files

{
  "id": "d9f76691297daf40d3205a45ad752498721fb7a648bb50865314b299c42843da",
  "url": "https://osv.dev/vulnerability/CVE-2026-59946",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Composer: Path traversal in package bin field lets dependencies chmod arbitrary host files",
    "summary": "Composer is a dependency Manager for the PHP language. Prior to 2.2.29 and 2.10.2, a Composer package bin entry containing .. path segments can resolve outside the package install directory and cause Composer's binary installation flow to chmod an existing host file to a world-readable and world-executable mode during composer install, update, or require. This issue is fixed in versions 2.2.29 and 2.10.2.",
    "evidence": "osv:CVE-2026-59946",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-59946",
      "aliases": [
        "BIT-composer-2026-59946",
        "CVE-2026-59946",
        "GHSA-gjfg-22fp-rrxx"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/composer/composer",
              "type": "GIT",
              "events": [
                {
                  "introduced": "32df3aa8cdbdaa16df9491b5e672e81c87f94c78"
                },
                {
                  "fixed": "ccbe57917efe30262ce80463fc4a6182c5ac29ed"
                },
                {
                  "introduced": "934ee6eed3c3ffd0aeccef7c1d255adcf0752b24"
                },
                {
                  "fixed": "8d4439f572a97670a9edc039eb3b093cc976b4bc"
                },
                {
                  "fixed": "502c6c4f699802d9cf464728b3e8a95674f919a0"
                },
                {
                  "fixed": "c50b1efd13ebd73f6dca19b31424c5a02bf93cc1"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.0"
                      },
                      {
                        "fixed": "2.2.29"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "2.3.0"
                      },
                      {
                        "fixed": "2.10.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "502c6c4f699802d9cf464728b3e8a95674f919a0"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c50b1efd13ebd73f6dca19b31424c5a02bf93cc1"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8d4439f572a97670a9edc039eb3b093cc976b4bc"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "2.10.2"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ccbe57917efe30262ce80463fc4a6182c5ac29ed"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "2.2.29"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.10.1",
            "2.10.0",
            "2.10.0-RC2",
            "2.10.0-RC1",
            "2.9.5",
            "2.9.4",
            "2.9.3",
            "2.9.2",
            "2.9.1",
            "2.9.0",
            "2.9.0-RC1",
            "2.8.9",
            "2.8.8",
            "2.8.7",
            "2.8.6",
            "2.8.5",
            "2.8.4",
            "2.8.3",
            "2.8.2",
            "2.8.1",
            "2.8.0",
            "2.7.9",
            "2.7.8",
            "2.7.7",
            "2.7.6",
            "2.7.5",
            "2.7.4",
            "2.7.3",
            "2.7.2",
            "2.7.1",
            "2.7.0",
            "2.6.5",
            "2.6.4",
            "2.6.3",
            "2.6.2",
            "2.6.1",
            "2.6.0",
            "2.5.2",
            "2.5.1",
            "2.5.0",
            "2.4.1",
            "2.4.0",
            "2.4.0-RC1",
            "2.3.5",
            "2.3.4",
            "2.3.3",
            "2.3.2",
            "2.3.1",
            "2.3.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59946.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:26.533679640Z",
      "provider": "osv",
      "references": [
        "https://github.com/composer/composer/releases/tag/2.10.2",
        "https://github.com/composer/composer/releases/tag/2.2.29",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59946.json",
        "https://github.com/composer/composer/security/advisories/GHSA-gjfg-22fp-rrxx",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-59946",
        "https://github.com/composer/composer/commit/502c6c4f699802d9cf464728b3e8a95674f919a0",
        "https://github.com/composer/composer/commit/c50b1efd13ebd73f6dca19b31424c5a02bf93cc1"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-22",
          "CWE-732"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59946.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-59946",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492947,
  "published_at": "2026-07-08T19:32:38.089+00:00"
}