oras-go: Hardlink entry with relative Linkname escapes extract dir via process CWD resolution in `oras-go` tar extraction

{
  "id": "0889679e3f375be4a2f9a5ae74f2d750f016f3f15c6a2251157413adc9eb68f0",
  "url": "https://osv.dev/vulnerability/CVE-2026-50163",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "oras-go: Hardlink entry with relative Linkname escapes extract dir via process CWD resolution in `oras-go` tar extraction",
    "summary": "oras-go is a Go library for managing OCI artifacts. Prior to 2.6.2, ensureLinkPath in content/file/utils.go:262-275 validates a hardlink target relative to the extract base but returns the unresolved target, causing os.Link(\"victim.secret\", \"/payload.tar.gz/evil_cwd_link\") to resolve header.Linkname against the process current working directory for a Typeflag=TypeLink entry such as Name=payload.tar.gz/evil_cwd_link and Linkname=\"victim.secret\" with io.deis.oras.content.unpack: \"true\", which can expose or tamper with files such as .env, .git/config, .aws/credentials, and ~/.ssh/config. This issue is fixed in version 2.6.2.",
    "evidence": "osv:CVE-2026-50163",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-50163",
      "aliases": [
        "CVE-2026-50163",
        "GHSA-fxhp-mv3v-67qp",
        "GO-2026-5880"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/oras-project/oras-go",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "105715ee12eac6895ec736a075285c34d9f2eeb6"
                },
                {
                  "fixed": "c463c654ab3ef34422c1764cd619806cebf20451"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.6.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c463c654ab3ef34422c1764cd619806cebf20451"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "105715ee12eac6895ec736a075285c34d9f2eeb6"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2.6.2"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.6.1",
            "v2.6.0",
            "v2.5.0",
            "v2.4.0",
            "v2.3.0",
            "v2.2.0",
            "v2.1.0",
            "v2.0.2",
            "v2.0.1",
            "v2.0.0",
            "v2.0.0-rc.6",
            "v2.0.0-rc.5",
            "v2.0.0-rc.4",
            "v2.0.0-rc.3",
            "v2.0.0-rc.2",
            "v2.0.0-rc.1",
            "v2.0.0-alpha",
            "v0.5.0",
            "v0.4.0",
            "v0.3.0",
            "v0.2.0",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50163.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:22.311667509Z",
      "provider": "osv",
      "references": [
        "https://github.com/oras-project/oras-go/releases/tag/v2.6.2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50163.json",
        "https://github.com/oras-project/oras-go/security/advisories/GHSA-fxhp-mv3v-67qp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50163",
        "https://github.com/oras-project/oras-go/commit/c463c654ab3ef34422c1764cd619806cebf20451",
        "https://github.com/oras-project/oras-go/pull/1232"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-22",
          "CWE-59"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50163.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-50163",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 488761,
  "published_at": "2026-07-17T19:36:01.254+00:00"
}