{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "libssh2"
              },
              {
                "fixed": "1.11.1"
              }
            ],
            "source": [
              "DESCRIPTION",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "9896c291e46787352151daa0fabf8be81d84cd09"
            },
            {
              "fixed": "a312b43325e3383c865a87bb1d26cb52e3292641"
            },
            {
              "fixed": "5e4776146552d898b9c0e1b313cd093fa8dc92d0"
            }
          ],
          "repo": "https://github.com/libssh2/libssh2",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-415"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66032.json"
  },
  "details": "libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites.",
  "id": "CVE-2026-66032",
  "modified": "2026-07-28T03:55:51.991637971Z",
  "published": "2026-07-24T16:32:39.596Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66032.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-66032"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/libssh2-double-free-heap-corruption-via-sftp-open"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libssh2/libssh2/commit/5e4776146552d898b9c0e1b313cd093fa8dc92d0"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libssh2/libssh2/pull/2180"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/libssh2/libssh2"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "libssh2 Double-Free Heap Corruption via sftp_open()"
}