--- id: CVE-2026-63076 title: |- Issue summary: OpenSSL CMP password based protection verification only checks whether the protectionAlg parameter was not NULL and not its ASN.1 type, before treating it as a PBMParameter summary: |- Issue summary: OpenSSL CMP password based protection verification only checks whether the protectionAlg parameter was not NULL and not its ASN.1 type, before treating it as a PBMParameter. A crafted message can contain 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' - url: 'https://access.redhat.com/errata/RHSA-2026:71603' 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: 0.01823 epssPercentile: 0.77837 --- ## Overview Issue summary: OpenSSL CMP password based protection verification only checks whether the protectionAlg parameter was not NULL and not its ASN.1 type, before treating it as a PBMParameter. A crafted message can contain a parameter of a different type, which is then dereferenced as an invalid pointer. Impact summary: A remote, unauthenticated attacker can crash an application acting as a CMP server that accepts PBM-protected messages, or a CMP client talking to a malicious or intercepted CMP server, resulting in a Denial of Service. CWE: CWE-476: NULL Pointer Dereference Description: When verifying the password-based MAC protection of a CMP message, OpenSSL library reads the protectionAlg algorithm parameter with X509_ALGOR_get0(), which returns both the parameter type and its value pointer. The value is then cast to an ASN1_STRING and treated as the expected PBMParameter after only checking that pointer is not NULL. The parameter type returned by X509_ALGOR_get0() was never consulted. This happens during protection verification, before any MAC is computed, so no knowledge of the PBM shared secret is required; the only precondition is that PBM verification is reachable. On the server side this is reached from OSSL_CMP_SRV_process_request() for any application that stands up a CMP server accepting PBM-protected messages, and on the client side from CMP response validation against a malicious or on-path (MITM) server. The reliable consequence is a denial of service; there is no memory disclosure, no controlled memory write, and no path to code execution. CMP is a specialized feature that an application must explicitly enable. FIPS impact: no As the CMP code lives outside the FIPS module boundary, no FIPS modules are affected by this CVE. ## 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` ## Remediation Upgrade past the affected range: - `openssl 4.0.2` ## Vendor advisories - **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) - **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) - **RHSA-2026:59641** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59641) - **RHSA-2026:59635** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59635) - **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 2026-09-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63076.json) - **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) - **RHSA-2026:71603** · Red Hat · fixed in: Red Hat Update Infrastructure 5 · released 2026-09-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:71603)