{
  "affected": [
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Alpine:v3.21",
        "name": "libssh2",
        "purl": "pkg:apk/alpine/libssh2?arch=source"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1-r2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Alpine:v3.22",
        "name": "libssh2",
        "purl": "pkg:apk/alpine/libssh2?arch=source"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1-r2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Alpine:v3.23",
        "name": "libssh2",
        "purl": "pkg:apk/alpine/libssh2?arch=source"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1-r3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Alpine:v3.24",
        "name": "libssh2",
        "purl": "pkg:apk/alpine/libssh2?arch=source"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1-r3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over 60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not apply to CPU-bound loops.",
  "id": "ALPINE-CVE-2026-55199",
  "modified": "2026-06-23T14:18:14.416606207Z",
  "published": "2026-06-17T20:17:28.520Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security.alpinelinux.org/vuln/CVE-2026-55199"
    }
  ],
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ],
  "upstream": [
    "CVE-2026-55199"
  ]
}