{"id":"CVE-2026-63076","title":"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","summary":"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 d…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"openssl","product":"openssl","affected":["openssl >= 3.0.0, < 3.0.22","openssl >= 3.4.0, < 3.4.7","openssl >= 3.5.0, < 3.5.8","openssl >= 3.6.0, < 3.6.4","openssl >= 4.0.0, < 4.0.2"],"patched":["openssl 4.0.2"],"published":"2026-08-25","updated":"2026-09-11","sourceUpdated":"2026-09-11T21:17:12.460","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63076","references":[{"url":"https://github.com/openssl/openssl/commit/37882aa2e0256e1072442a8f62f7db45b995c45b","label":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/a17cc8d612ecff6d94a9b7ca8b5283ddf5ff570e","label":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/a1f348ccb328c3afbd4ba6883f9b7c813c043259","label":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/a7af46a92d0ce19a90e669ef56d2576a07924226","label":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/cdacfff557389abfa9e4615abded2ec984517d6c","label":"openssl-security@openssl.org"},{"url":"https://openssl-library.org/news/secadv/20260825.txt","label":"openssl-security@openssl.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63076.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-63076"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517561"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63076"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63076"},{"url":"https://access.redhat.com/errata/RHSA-2026:67154"},{"url":"https://access.redhat.com/errata/RHSA-2026:67165"},{"url":"https://access.redhat.com/errata/RHSA-2026:59641"},{"url":"https://access.redhat.com/errata/RHSA-2026:59635"},{"url":"https://access.redhat.com/errata/RHSA-2026:67956"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-08-25T14:37:28.943884Z"},"ingestedAt":"2026-09-13T09:25:10.554Z","epss":0.0135,"epssPercentile":0.69837,"slug":"CVE-2026-63076","body":"## Overview\n\nIssue 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.\n\n## Affected\n\n- `openssl >= 3.0.0, < 3.0.22`\n- `openssl >= 3.4.0, < 3.4.7`\n- `openssl >= 3.5.0, < 3.5.8`\n- `openssl >= 3.6.0, < 3.6.4`\n- `openssl >= 4.0.0, < 4.0.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `openssl 4.0.2`\n\n## Vendor advisories\n\n- **RHSA-2026:67154** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67154)\n- **RHSA-2026:67165** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67165)\n- **RHSA-2026:59641** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59641)\n- **RHSA-2026:59635** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59635)\n- **Red Hat VEX** · Moderate · affected: Red Hat Developer Hub, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat JBoss Core Services, Red Hat JBoss Web Server 6, Red Hat JBoss Web Server 7, … · no fix planned: Red Hat JBoss Core Services, Red Hat JBoss Web Server 6, Red Hat JBoss Web Server 7, Red Hat Developer Hub, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63076.json)\n- **RHSA-2026:67956** · Red Hat · fixed in: Red Hat Update Infrastructure 5 · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:67956)","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.3,"likelihood":0.3,"exploitation":0,"ransomware":0},"changes":[]}