{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "OpenSSL",
          "vendor": "OpenSSL",
          "versions": [
            {
              "lessThan": "4.0.2",
              "status": "affected",
              "version": "4.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.6.4",
              "status": "affected",
              "version": "3.6.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.5.8",
              "status": "affected",
              "version": "3.5.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.4.7",
              "status": "affected",
              "version": "3.4.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.0.22",
              "status": "affected",
              "version": "3.0.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Ying Dong"
        },
        {
          "lang": "en",
          "type": "reporter",
          "value": "Bhabani Sankar Das"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Daniel Kubec"
        }
      ],
      "datePublic": "2026-08-25T13:36:16+02:00",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Issue summary: OpenSSL CMP password based protection verification only<br>checks whether the protectionAlg parameter was not NULL and not its<br>ASN.1 type, before treating it as a PBMParameter. A crafted message can<br>contain a parameter of a different type, which is then dereferenced as an<br>invalid pointer.<br><br>Impact summary: A remote, unauthenticated attacker can crash an application<br>acting as a CMP server that accepts PBM-protected messages, or a CMP client<br>talking to a malicious or intercepted CMP server, resulting in a Denial of<br>Service.<br><br>CWE: CWE-476: NULL Pointer Dereference<br><br>Description: When verifying the password-based MAC protection of a CMP<br>message, OpenSSL library reads the protectionAlg algorithm parameter with<br>X509_ALGOR_get0(), which returns both the parameter type and its value<br>pointer. The value is then cast to an ASN1_STRING and treated as the<br>expected PBMParameter after only checking that pointer is not NULL. The<br>parameter type returned by X509_ALGOR_get0() was never consulted.<br><br>This happens during protection verification, before any MAC is computed, so<br>no knowledge of the PBM shared secret is required; the only precondition is<br>that PBM verification is reachable. On the server side this is reached from<br>OSSL_CMP_SRV_process_request() for any application that stands up a CMP<br>server accepting PBM-protected messages, and on the client side from CMP<br>response validation against a malicious or on-path (MITM) server. The<br>reliable consequence is a denial of service; there is no memory disclosure,<br>no controlled memory write, and no path to code execution. CMP is a<br>specialized feature that an application must explicitly enable.<br><br>FIPS impact: no<br>As the CMP code lives outside the FIPS module boundary, no FIPS modules<br>are affected by this CVE."
            }
          ],
          "value": "Issue summary: OpenSSL CMP password based protection verification only\nchecks whether the protectionAlg parameter was not NULL and not its\nASN.1 type, before treating it as a PBMParameter. A crafted message can\ncontain a parameter of a different type, which is then dereferenced as an\ninvalid pointer.\n\nImpact summary: A remote, unauthenticated attacker can crash an application\nacting as a CMP server that accepts PBM-protected messages, or a CMP client\ntalking to a malicious or intercepted CMP server, resulting in a Denial of\nService.\n\nCWE: CWE-476: NULL Pointer Dereference\n\nDescription: When verifying the password-based MAC protection of a CMP\nmessage, OpenSSL library reads the protectionAlg algorithm parameter with\nX509_ALGOR_get0(), which returns both the parameter type and its value\npointer. The value is then cast to an ASN1_STRING and treated as the\nexpected PBMParameter after only checking that pointer is not NULL. The\nparameter type returned by X509_ALGOR_get0() was never consulted.\n\nThis happens during protection verification, before any MAC is computed, so\nno knowledge of the PBM shared secret is required; the only precondition is\nthat PBM verification is reachable. On the server side this is reached from\nOSSL_CMP_SRV_process_request() for any application that stands up a CMP\nserver accepting PBM-protected messages, and on the client side from CMP\nresponse validation against a malicious or on-path (MITM) server. The\nreliable consequence is a denial of service; there is no memory disclosure,\nno controlled memory write, and no path to code execution. CMP is a\nspecialized feature that an application must explicitly enable.\n\nFIPS impact: no\nAs the CMP code lives outside the FIPS module boundary, no FIPS modules\nare affected by this CVE."
        }
      ],
      "metrics": [
        {
          "format": "other",
          "other": {
            "content": {
              "text": "Moderate"
            },
            "type": "https://openssl-library.org/policies/general/security-policy/"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-476",
              "description": "CWE-476 NULL Pointer Dereference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "orgId": "00000000-0000-4000-9000-000000000000",
        "shortName": "openssl"
      },
      "references": [
        {
          "name": "OpenSSL Advisory",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://openssl-library.org/news/secadv/20260825.txt"
        },
        {
          "name": "4.0.2 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/a17cc8d612ecff6d94a9b7ca8b5283ddf5ff570e"
        },
        {
          "name": "3.6.4 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/a7af46a92d0ce19a90e669ef56d2576a07924226"
        },
        {
          "name": "3.5.8 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/cdacfff557389abfa9e4615abded2ec984517d6c"
        },
        {
          "name": "3.4.7 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/a1f348ccb328c3afbd4ba6883f9b7c813c043259"
        },
        {
          "name": "3.0.22 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/37882aa2e0256e1072442a8f62f7db45b995c45b"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Invalid Pointer Dereference in CMP Server via Crafted protectionAlg",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "00000000-0000-4000-9000-000000000000",
    "cveId": "CVE-2026-63076",
    "requesterUserId": "00000000-0000-4000-9000-000000000000",
    "serial": 1,
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}