CVE-2026-85088CVE-2026-85088

Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift. Both libraries install a default access manager for client sockets — TSSLSocketFactory does so in C++, and the accessManager property does so in D — which compares the peer certificate against the host name that was connected to. That comparison walks the subjectAltName dNSName entries first and consults the certificate Common Name afterwards. A name that does not match yields a "skip" result rather than a rejection, so a certificate whose subjectAltName entries are all present and all non-matching falls through to the Common Name, which can then satisfy the check. RFC 6125 section 6.4.4, and RFC 9525 section 2, require that the Common Name is not consulted when a dNSName subjectAltName is present. A certificate carrying subjectAltName entries for one name and a Common Name for another is therefore accepted for a connection to the second name. Exploitation requires an attacker