Vercel deepsec before 1.1.17 Arbitrary File Write via Symlink in Sandbox Tarball Extraction

{
  "id": "75fb266341ac67bad07a9ef0d36c9ca52b8184fc05acd797c1238287835c49ad",
  "url": "https://osv.dev/vulnerability/CVE-2026-109375",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vercel deepsec before 1.1.17 Arbitrary File Write via Symlink in Sandbox Tarball Extraction",
    "summary": "Vercel deepsec from 0.1.0 before 1.1.17 contains a link following vulnerability in extractTarballLocally that allows sandboxed code to write files outside the sandbox by planting links in result tarballs. Attackers controlling sandbox code, such as a prompt-injected coding agent, can plant symbolic or hard links in the host data directory to write arbitrary files on the orchestrator host.",
    "evidence": "osv:CVE-2026-109375",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-109375",
      "aliases": [
        "CVE-2026-109375"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/vercel-labs/deepsec",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "c5a4e4220ece72aee67c2ea21f4340e65f673fc1"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "c5a4e4220ece72aee67c2ea21f4340e65f673fc1"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-109375.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:51.135717598Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109375.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-109375",
        "https://www.vulncheck.com/advisories/vercel-deepsec-before-1.1.17-arbitrary-file-write-via-symlink-in-sandbox-tarball-extraction",
        "https://github.com/vercel-labs/deepsec/commit/c5a4e4220ece72aee67c2ea21f4340e65f673fc1",
        "https://github.com/vercel-labs/deepsec/pull/46",
        "https://github.com/vercel-labs/deepsec/pull/47",
        "https://github.com/vercel-labs/deepsec"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-59"
        ],
        "cna_assigner": "VulnCheck",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0.1.0"
                  },
                  {
                    "fixed": "1.1.17"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0.1.0"
                  },
                  {
                    "fixed": "1.1.17"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109375.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-109375",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 519947,
  "published_at": "2026-10-12T20:55:08.596+00:00"
}