CVE-2026-85088

Published Oct 2, 2026 Modified Oct 2, 2026 CWE-295 CWE-297

Description

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 positioned on the network path who holds a certificate that chains to a certificate authority in the client's trust store and whose Common Name matches the connected host name. Public certificate authorities have not issued on Common Name alone for many years, so this is principally a concern for deployments using a private or enterprise public-key infrastructure. This issue affects the C++ library of Apache Thrift from 0.7.0 through 0.24.0 and the D library from 0.9.0 through 0.24.0. Users should upgrade to 0.25.0.

Is your site exposed to CVE-2026-85088?

Run a free security scan — no signup, results in seconds.

Weakness Type (CWE)

CWE-295 CWE-295
CWE-297 CWE-297

References

Frequently Asked Questions

What is CVE-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 positioned on the network path who holds a certificate that chains to a certificate authority in the client's trust store and whose Common Name matches the connected host name. Public certificate authorities have not issued on Common Name alone for many years, so this is principally a concern for deployments using a private or enterprise public-key infrastructure. This issue affects the C++ library of Apache Thrift from 0.7.0 through 0.24.0 and the D library from 0.9.0 through 0.24.0. Users should upgrade to 0.25.0.
How do I check if I'm vulnerable to CVE-2026-85088? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2026-85088 — free, no signup required.