{
  "affected": [
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Alpine:v3.24",
        "name": "wolfssh",
        "purl": "pkg:apk/alpine/wolfssh?arch=source"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.2.0"
            },
            {
              "fixed": "1.6.0-r0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "src/internal.c in wolfSSL wolfSSH through 1.5.0 admits the server-to-client Diffie-Hellman group exchange messages SSH_MSG_KEX_DH_GEX_GROUP (31) and SSH_MSG_KEX_DH_GEX_REPLY (33) when a server receives them from an unauthenticated client. IsMessageAllowedServer() applies no direction check to the key exchange message range: when the peer is keying and no particular message is expected, which is the state a server is in for the whole window after it processes the client's KEXINIT because nothing sets handshake-\u003eexpectMsgId there, the function falls out of its expectation branch without a verdict and reaches a numeric bound that admits every message id from 30 through 34. A client that negotiates diffie-hellman-group-exchange-sha256 and then sends message 31 makes the server run the client-side handler DoKexDhGexGroup(), which validates the attacker-supplied group with two 8-round Miller-Rabin primality tests, one on p and one on (p-1)/2, on a value of up to 8192 bits. The handler then returns success: the server stores the attacker's prime and generator, generates a Diffie-Hellman key pair in the attacker's group, and sends the client-role message SSH_MSG_KEX_DH_GEX_INIT (32) back to the attacker. Published RFC 3526 safe primes are the worst-case input and cost the attacker nothing to obtain. The primality validation was added in 1.5.0; versions from 1.2.0 through 1.4.22 admit the same message and enter the same client-role path without the primality cost. Message 33 is admitted as well, but on a server it is rejected before any cryptography because no public key check callback is registered, so it carries no comparable cost. Builds that define WOLFSSH_NO_DH_GEX_SHA256, which is implied by WOLFSSH_NO_DH or NO_SHA256, are unaffected.",
  "id": "ALPINE-CVE-2026-84897",
  "modified": "2026-11-03T06:18:02.148484091Z",
  "published": "2026-10-07T03:17:00.067Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security.alpinelinux.org/vuln/CVE-2026-84897"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-84897"
  ]
}