CVE-2026-66392 Apache bRPC: TLS Client Accepts Certificates for Mismatched Peer Names
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-66392?
CVE-2026-66392 is a vulnerability in Apache bRPC, published on 21 Oct 2026.
Official description
Apache bRPC versions before 1.18.0 validate the server certificate chain when client TLS peer verification is enabled, but do not bind the certificate to an expected DNS name or IP address. A network attacker who can redirect or intercept a connection and who possesses a certificate issued by a CA trusted by the client for another name may impersonate the requested TLS endpoint.
Affected Scenarios: Applications use a bRPC client Channel to connect to an untrusted network with certificate verification enabled and trust a CA that can issue certificates for identities other than the intended endpoint.
How to Fix: Upgrade to Apache bRPC 1.18.0 and enable VERIFY_PEER with a positive verify_depth. HTTPS Channels automatically verify the certificate against the host in the Channel URL. Callers may set VerifyOptions::expected_peer_name explicitly when the certificate identity differs from the URL host. Alternatively, apply the patch from https://github.com/apache/brpc/pull/3408 .
Note: The new option performs DNS SAN or IP SAN verification during the TLS handshake. Configurations that set expected_peer_name while peer verification is disabled are rejected.
Weakness: CWE-297
Which versions are affected by CVE-2026-66392?
How do I fix CVE-2026-66392?
No fix has been published for CVE-2026-66392 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-66392 being exploited?
There is no known exploitation of CVE-2026-66392 in the wild and no public exploit code.
Sources
Also known as GHSA-qv5c-vj5j-fg9q.