{"cve":"CVE-2026-42769","nvd":{"published":"2026-06-09T17:17:08.377","modified":"2026-07-23T08:10:00.137","status":"Analyzed","description":"Issue Summary: An error in the callback used to verify the certificate\nprovided in a Root CA key update Certificate Management Protocol (CMP)\nmessage response rendered the certificate validation ineffectual, which\ncould lead to escalation of credentials from the Registration Authority (RA)\nlevel to the root Certification Authority (root CA) level.\n\nImpact Summary: The Registration Autority could replace the root CA\ncertificate for the CMP clients with an arbitrary root CA certificate.\n\nOne of the parts of the Certificate Management Protocol (CMP), specified in\nRFC 9810, is Root Certification Authority (root CA) key Rollover,\nwhich is sent by the server in a message with type 'id-it-rootCaKeyUpdate'.\nAs part of these messages, 'newWithOld' certificate, the new root CA\ncertificate signed with the old root CA key, is provided, and verifying its\nsignature is crucial for transferring the trust from the old CA key to the\nnew one.\n\nThe 'id-it-rootCaKeyUpdate' messages are expected to be processed with\nOSSL_CMP_get1_rootCaKeyUpdate(), that is expected to verify the 'newWithOld'\ncertificate.  A typo in the certificate chain building code led to adding\nan incorrect certificate ('newWithOld' instead of 'oldRoot') to the\ncertificate chain, rendering the certificate verification process ineffectual\n(only the issuer name and the algorithm OIDs were verified by other parts\nof the verification code).\n\nAn attacker who already has credentials that satisfy the CMP message\nprotection checks can generate a new key pair and use a crafted self-signed\ncertificate in its 'id-it-rootCaKeyUpdate' CMP messages which affected CMP\nclients would accept as a new trust anchor.\n\nSignificant preconditions for the attack (having valid RA-level credentials)\nare the reason the issue was assigned Low severity.\n\nThe FIPS modules are not affected by this issue, as the affected code is\noutside the OpenSSL FIPS module boundary.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","score":5.3},"cwes":["CWE-295"],"references":["https://github.com/openssl/openssl/commit/54d0989997e5fc26057009a9782c3441ce3842fb","https://github.com/openssl/openssl/commit/777b363b16fcf2153bb3ded39dc3838713667c44","https://github.com/openssl/openssl/commit/d35cd473a271bf3ce7bf3d32af53217fb83ae92c","https://github.com/openssl/openssl/commit/d531f21c0fe99067a66fc0ff1161ef127f9cd70b","https://openssl-library.org/news/secadv/20260609.txt"],"products":["openssl:openssl"],"source":"nvd","synced_at":"2026-10-19T22:38:48.522727527+00:00"},"epss":{"cve":"CVE-2026-42769","score":0.00544,"percentile":0.45687,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}