{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "1.1.1"
                  },
                  {
                    "fixed": "1.1.1zk"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              },
              {
                "range": [
                  {
                    "introduced": "1.0.2"
                  },
                  {
                    "fixed": "1.0.2zt"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              },
              {
                "range": [
                  {
                    "fixed": "36e15b618decdff1b116eead6747718e6e729ad2"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "range": [
                  {
                    "fixed": "a8531368ddb1f86d2a2782a8b693926bb67b59e7"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "range": [
                  {
                    "fixed": "a0051cfe699bf5a047bc1c4faef65f80f7987366"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              }
            ]
          },
          "events": [
            {
              "introduced": "e04bd3433fd84e1861bf258ea37928d9845e6a86"
            },
            {
              "fixed": "e04bd3433fd84e1861bf258ea37928d9845e6a86"
            },
            {
              "introduced": "e818b74be2170fbe957a07b0da4401c2b694b3b8"
            },
            {
              "fixed": "e818b74be2170fbe957a07b0da4401c2b694b3b8"
            },
            {
              "fixed": "36e15b618decdff1b116eead6747718e6e729ad2"
            },
            {
              "fixed": "a8531368ddb1f86d2a2782a8b693926bb67b59e7"
            },
            {
              "fixed": "a0051cfe699bf5a047bc1c4faef65f80f7987366"
            }
          ],
          "repo": "https://github.com/openssl/openssl",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "openssl",
    "cwe_ids": [
      "CWE-835"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107496.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "range": [
              {
                "introduced": "4.1.0"
              },
              {
                "fixed": "4.1.1"
              },
              {
                "introduced": "4.0.0"
              },
              {
                "fixed": "4.0.4"
              },
              {
                "introduced": "3.5.0"
              },
              {
                "fixed": "3.5.10"
              },
              {
                "introduced": "3.0.0"
              },
              {
                "fixed": "3.0.24"
              }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StandardRange"
          }
        ]
      }
    ]
  },
  "details": "Issue summary: Encrypting a CMS message to an EC certificate whose group order\nis 1 may cause CMS_encrypt() or CMS_encrypt_ex() to loop indefinitely.\n\nImpact summary: An attacker able to supply the recipient certificate to an\napplication performing CMS encryption can cause that application to loop\nindefinitely, consuming CPU and resulting in Denial of Service.\n\nCWE: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')\n\nDescription: CMS_encrypt() and CMS_encrypt_ex() encrypt a message to one or\nmore recipient certificates and, for an EC recipient, generate an ephemeral\nkey in the recipient's group. If the certificate declares a group order of 1,\nrandom scalar generation can only produce zero. The key generation routine\nthen retries without limit while waiting for a nonzero private scalar, so the\ncall never returns.\n\nThe OpenSSL TLS and QUIC implementations do not use this path. An application\nis exposed only if it calls CMS_encrypt() or CMS_encrypt_ex() with a recipient\ncertificate whose EC parameters are attacker-controlled. Certificates with\nnormal EC group orders do not trigger the loop.\n\nOpenSSL 4.0 and later reject unknown explicit EC groups in default builds.\nThese versions are affected only when configured with the\nenable-ec_explicit_curves option.\n\nThe result is a hang that consumes a CPU core until the process is\ninterrupted, a Denial of Service. The severity is Low because the attacker\nmust supply the recipient certificate and the application must choose to\nencrypt to it; ordinary CMS encryption to trusted recipients is unaffected.\n\nThe fix makes EC key generation fail when the group has no valid nonzero\nprivate scalar, instead of retrying indefinitely.\n\nFIPS impact: no\nThe FIPS modules in 4.1, 4.0, 3.5 and 3.0 are not affected. The FIPS provider\ndoes not support arbitrary explicit EC domain parameters, so an order-1 group\nis rejected during key import before the vulnerable key generation path is\nreached.",
  "id": "CVE-2026-107496",
  "modified": "2026-11-12T02:30:33.702130474Z",
  "published": "2026-11-10T18:14:18.207Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107496.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-107496"
    },
    {
      "type": "ADVISORY",
      "url": "https://openssl-library.org/news/secadv/20261110.txt"
    },
    {
      "type": "FIX",
      "url": "https://github.com/openssl/openssl/commit/36e15b618decdff1b116eead6747718e6e729ad2"
    },
    {
      "type": "FIX",
      "url": "https://github.com/openssl/openssl/commit/a0051cfe699bf5a047bc1c4faef65f80f7987366"
    },
    {
      "type": "FIX",
      "url": "https://github.com/openssl/openssl/commit/a8531368ddb1f86d2a2782a8b693926bb67b59e7"
    }
  ],
  "schema_version": "1.9.2",
  "summary": "Infinite Loop in CMS_encrypt() With an EC Group Order of 1"
}