{"id":"ALPINE-CVE-2026-63076","details":"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.","modified":"2026-09-17T17:30:03.585466112Z","published":"2026-08-25T13:19:26.543Z","upstream":["CVE-2026-63076"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2026-63076"}],"affected":[{"package":{"name":"openssl","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/openssl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.3.7-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2026-63076.json"}},{"package":{"name":"openssl","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/openssl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.5.8-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2026-63076.json"}},{"package":{"name":"openssl","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/openssl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.5.8-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2026-63076.json"}},{"package":{"name":"openssl","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/openssl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.5.8-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2026-63076.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}