{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "source": "REFERENCES"
          },
          "events": [
            {
              "introduced": "c9b26a46928bfcd546773571e09c1d05f4cd9fb7"
            },
            {
              "fixed": "5f5a2136c7cf5991b6e8a30d645ca9f8e74b0785"
            },
            {
              "fixed": "6232a6498015e559743bec4f4fbec9138837cec8"
            },
            {
              "fixed": "c9b26a46928bfcd546773571e09c1d05f4cd9fb7"
            }
          ],
          "repo": "https://github.com/hexpm/hex",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-rw8q-hg7m-cxgr"
  ],
  "database_specific": {
    "cna_assigner": "EEF",
    "cwe_ids": [
      "CWE-295"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103503.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "0.20.2"
          },
          {
            "fixed": "2.5.2"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Improper Certificate Validation vulnerability in hexpm hex allows an attacker who can intercept HTTPS connections, and holds a certificate for a Hex host issued by a CA in Hex's bundled CA store, to impersonate that host to users who set cacerts_path to a CA store that leaves that CA out.\n\ncacerts_path (HEX_CACERTS_PATH) is documented as the path to the CA certificate store, used instead of the CA bundle that ships with Hex. Hex.HTTP.SSL.ssl_opts/1 passes the configured store as the cacerts option, but builds the partial_chain callback from the bundled store whether cacerts_path is set or not. Hex.HTTP.SSL.partial_chain/2 accepts a server chain when any certificate in it has the same public key as a bundled CA certificate, so a chain that leads to a bundled CA passes verification although the configured store doesn't contain that CA. Hostname verification still applies.\n\nThis issue affects hex: from 0.20.2 before 2.5.2.",
  "id": "CVE-2026-103503",
  "modified": "2026-10-15T02:31:06.310277719Z",
  "published": "2026-10-12T15:17:45.545Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-103503.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-103503"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103503.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/hexpm/hex/security/advisories/GHSA-rw8q-hg7m-cxgr"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103503"
    },
    {
      "type": "FIX",
      "url": "https://github.com/hexpm/hex/commit/5f5a2136c7cf5991b6e8a30d645ca9f8e74b0785"
    },
    {
      "type": "FIX",
      "url": "https://github.com/hexpm/hex/commit/6232a6498015e559743bec4f4fbec9138837cec8"
    },
    {
      "type": "FIX",
      "url": "https://github.com/hexpm/hex/commit/c9b26a46928bfcd546773571e09c1d05f4cd9fb7"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/hexpm/hex"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Hex trusts its bundled CA certificates when cacerts_path is set"
}