{
  "cveId": "CVE-2026-66034",
  "url": "https://patchblox.com/security/cve/CVE-2026-66034",
  "summary": "CVE-2026-66034 is fixed in 11 products on 1 platform, first by libssh2-1t64 1.11.0-4.1ubuntu0.24.04.3, released July 14, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "libssh2 Heap Out-of-Bounds Read via publickey subsystem",
  "description": "libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In libssh2_publickey_list_fetch(), the version 1 response parser reads a server-controlled comment_len value and advances the parse pointer without verifying sufficient bytes remain in the buffer, causing the out-of-bounds read to leak heap pointers from adjacent allocations defeating ASLR, followed by heap allocator state corruption when the error cleanup path frees an uninitialized pointer from a non-zeroed realloc() region.",
  "published": "2026-07-24T10:17:00Z",
  "severity": "Important",
  "cvss": 7.5,
  "cwe": "Out-of-bounds Read",
  "epss": 0.00402,
  "epssPercentile": 0.34733,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66034",
  "fixes": [
    {
      "platform": "linux",
      "product": "cargo-c",
      "release": "amzn 2023",
      "fixedVersion": "0.10.21-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-2064",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2064",
      "released": "2026-08-17T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "cargo-c-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "0.10.21-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-2064",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2064",
      "released": "2026-08-17T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "1.10.0-3\u002Bdeb12u1",
      "fix": "DEBIAN-CVE-2026-66034",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-66034",
      "released": "2026-08-01T14:28:19Z"
    },
    {
      "platform": "linux",
      "product": "libssh2",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1.11.1-1\u002Bdeb13u2",
      "fix": "DEBIAN-CVE-2026-66034",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-66034",
      "released": "2026-08-01T14:28:19Z"
    },
    {
      "platform": "linux",
      "product": "libssh2",
      "release": "Debian 14",
      "fixedVersion": "1.11.1-5",
      "fix": "DEBIAN-CVE-2026-66034",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-66034",
      "released": "2026-08-01T14:28:19Z"
    },
    {
      "platform": "linux",
      "product": "libssh2",
      "release": "amzn 2023",
      "fixedVersion": "1.10.0-1.amzn2023.0.6",
      "fix": "ALAS2023-2026-2056",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2056",
      "released": "2026-08-17T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-1",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1.8.0-1ubuntu0.1\u002Besm1",
      "fix": "libssh2-1 1.8.0-1ubuntu0.1\u002Besm1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libssh2-1-1.8.0-1ubuntu0.1-esm1",
      "released": "2026-07-24T10:17:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-1",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1.8.0-2.1ubuntu0.1\u002Besm1",
      "fix": "libssh2-1 1.8.0-2.1ubuntu0.1\u002Besm1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libssh2-1-1.8.0-2.1ubuntu0.1-esm1",
      "released": "2026-07-24T10:17:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-1",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "1.10.0-3ubuntu0.1",
      "fix": "libssh2-1 1.10.0-3ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-libssh2-1-1.10.0-3ubuntu0.1",
      "released": "2026-07-24T10:17:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-1t64",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "1.11.0-4.1ubuntu0.24.04.3",
      "fix": "libssh2-1t64 1.11.0-4.1ubuntu0.24.04.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-libssh2-1t64-1.11.0-4.1ubuntu0.24.04.3",
      "released": "2026-07-14T16:28:35Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-1t64",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.11.1-1ubuntu0.26.04.3",
      "fix": "libssh2-1t64 1.11.1-1ubuntu0.26.04.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-libssh2-1t64-1.11.1-1ubuntu0.26.04.3",
      "released": "2026-07-24T10:17:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1.10.0-1.amzn2023.0.6",
      "fix": "ALAS2023-2026-2056",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2056",
      "released": "2026-08-17T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-debugsource",
      "release": "amzn 2023",
      "fixedVersion": "1.10.0-1.amzn2023.0.6",
      "fix": "ALAS2023-2026-2056",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2056",
      "released": "2026-08-17T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-devel",
      "release": "amzn 2023",
      "fixedVersion": "1.10.0-1.amzn2023.0.6",
      "fix": "ALAS2023-2026-2056",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2056",
      "released": "2026-08-17T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2-docs",
      "release": "amzn 2023",
      "fixedVersion": "1.10.0-1.amzn2023.0.6",
      "fix": "ALAS2023-2026-2056",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2056",
      "released": "2026-08-17T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libssh2_org",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "1.11.1-160000.5.1",
      "fix": "OPENSUSE-SU-2026:21549-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21549-1",
      "released": "2026-08-10T15:24:32Z"
    },
    {
      "platform": "linux",
      "product": "libssh2_org",
      "release": "sles 15.6",
      "fixedVersion": "1.11.0-150600.20.6.1",
      "fix": "SUSE-SU-2026:3541-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-3541-1",
      "released": "2026-08-10T12:50:14Z"
    },
    {
      "platform": "linux",
      "product": "libssh2_org",
      "release": "sles 15.7",
      "fixedVersion": "1.11.0-150600.20.6.1",
      "fix": "SUSE-SU-2026:3541-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-3541-1",
      "released": "2026-08-10T12:50:14Z"
    },
    {
      "platform": "linux",
      "product": "libssh2_org",
      "release": "sles 16.0",
      "fixedVersion": "1.11.1-160000.5.1",
      "fix": "SUSE-SU-2026:23225-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23225-1",
      "released": "2026-08-10T15:24:14Z"
    },
    {
      "platform": "linux",
      "product": "rust-cargo-c-debugsource",
      "release": "amzn 2023",
      "fixedVersion": "0.10.21-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-2064",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2064",
      "released": "2026-08-17T09:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}