{"id":"CVE-2026-75805","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-75805","generatedAt":"2026-10-28T02:57:34.948Z","title":"Impact summary: The NULL pointer dereference happens on a read which leads to a crash and a Denial of Service for the affected client application.","description":"Issue summary: A CMP client that requests certificate revocation on the basis\nof a PKCS#10 CSR may dereference a NULL pointer and terminate abnormally when\nprocessing a crafted revocation response. \n\nImpact summary: The NULL pointer dereference happens on a read which \nleads to a crash and a Denial of Service for the affected client application.\n\nCWE: CWE-476: NULL-pointer dereference\n\nDescription: A CMP client revoking a certificate has to tell the server which\ncertificate to revoke, and may do so by supplying a PKCS#10 CSR instead of the\ncertificate itself or its issuer name and serial number. This is\n'openssl cmp -cmd rr -csr <file>' on the command line, or\nOSSL_CMP_exec_RR_ses() with the certificate supplied via\nOSSL_CMP_CTX_set1_p10CSR() through the API.\n\nA CSR does not contain the issuer name and serial number of the certificate,\nso the client does not send them. A server may optionally name the\ncertificate it revoked in its response, and the client then compares that\nname against what it sent. Having sent neither an issuer name nor a serial\nnumber, it has nothing to compare against, and a server returning a specially\ncrafted name causes the client to read from a NULL pointer and crash.\n\nThe revocation response is checked for valid message protection before\nthe affected code is reached, so an attacker must be a malicious or\ncompromised CMP server, or a man-in-the-middle in possession of the\nsecret used for message protection. Clients that identify the certificate\nto be revoked by a certificate or by issuer and serial number rather\nthan by a PKCS#10 CSR are not affected.\n\nFIPS impact: no\nNo FIPS modules are affected by this issue, as the CMP protocol\nimplementation is outside the OpenSSL FIPS module boundary.","published":"2026-09-29T16:17:11.000Z","lastModified":"2026-10-08T01:20:24.000Z","status":"Analyzed","sourceIdentifier":"openssl-security@openssl.org","cvss":{"version":"3.1","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},"cwe":["CWE-476"],"affected":["openssl/openssl"],"epss":{"score":0.00324,"percentile":0.25276,"date":"2026-10-26","history":[{"date":"2026-09-30","score":0.00222,"percentile":0.11535}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.32%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-29T16:17:11.000Z","detail":{"score":"5.3","severity":"MEDIUM","publishedAt":"2026-09-29T16:17:11.063Z"},"summary":"New CVE, medium severity (CVSS 5.3)."}],"references":[{"url":"https://github.com/openssl/openssl/commit/7588db7fef14209c3caa3a101d11a02006b19166","tags":["Patch"],"source":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/7ca0ccb5172a577e9b87267d77bfe21e5481a5e7","tags":["Patch"],"source":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/9eb2a8a9b86136cdb39d6d7d50644dd66941cdc3","tags":["Patch"],"source":"openssl-security@openssl.org"},{"url":"https://github.com/openssl/openssl/commit/abf02872a4b71767ecc72293424420f5b009190f","tags":["Patch"],"source":"openssl-security@openssl.org"},{"url":"https://openssl-library.org/news/secadv/20260929.txt","tags":["Vendor Advisory"],"source":"openssl-security@openssl.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-75805","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}