{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:libreswan:libreswan:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "5.3.1"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "de24519eb4ff49803a21d75e880c87834cf33beb"
            }
          ],
          "repo": "https://github.com/libreswan/libreswan",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {},
  "details": "Libreswan, via the function RSA_authenticate_hash_signature_raw_rsa(), did not correctly verify the length of the authentication hash when the SIG payload of an IKEv1 packet was encoded using PKCS #1 RSA Encryption as per RFC 2313. A remote attacker can use a variation on the Bleichenbacher attack to forge the SIG payload when small public exponents are being used (e.g., e=3), which could lead to impersonation. Additionally, a remote attacker, by encoding a shorter than expected hash in the SIG payload, could trigger an assertion leading to denial-of-service. The daemon aborts and restarts; continued exploitation causes sustained denial of service. Remote code execution is not possible. X.509 certificate verifications of remote IKE peers are not affected.",
  "id": "CVE-2026-50721",
  "modified": "2026-07-11T03:54:18.550881859Z",
  "published": "2026-07-02T22:16:43.367Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://libreswan.org/security/CVE-2026-50721/"
    },
    {
      "type": "ADVISORY",
      "url": "https://libreswan.org/security/CVE-2026-50721/CVE-2026-50721.txt"
    },
    {
      "type": "ADVISORY",
      "url": "https://libreswan.org/security/CVE-2026-50722/CVE-2026-50722.txt"
    },
    {
      "type": "ARTICLE",
      "url": "https://www.rfc-editor.org/rfc/rfc2313"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}