{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "0.27.0"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "aca07679a6dd281ee6411f5e7de2ed0ee796bee8"
            }
          ],
          "repo": "https://github.com/opensc/opensc",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-72x5-fwjx-2459"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-126"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66038.json"
  },
  "details": "OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (high nibble) and value length (low nibble). With a 1-byte buffer {0x0A}, the encoded element claims tag=0 and length=10 but no value bytes follow. Calling sc_compacttlv_find_tag with search tag 0x00 returns a pointer equal to buf+1 and outlen=10 without verifying that the claimed value length fits within the remaining buffer. In cases where the sc_compacttlv_find_tag is provided untrusted data (such as being read from cards/files), attackers may be able to influence it to return out-of-bounds pointers leading to downstream memory corruption when subsequent code tries to dereference the pointer. This issue has been patched in version 0.27.0.",
  "id": "CVE-2025-66038",
  "modified": "2026-04-01T23:10:11.083804629Z",
  "published": "2026-03-30T17:03:55.914Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66038.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/OpenSC/OpenSC/commit/6db171bcb6fd7cb3b51098fefbb3b28e44f0a79c"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/OpenSC/OpenSC/security/advisories/GHSA-72x5-fwjx-2459"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OpenSC/OpenSC/wiki/CVE-2025-66038"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-66038"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OpenSC: `sc_compacttlv_find_tag` can return out-of-bounds pointers"
}