CVE-2026-39828 is a vulnerability in the golang.org/x/crypto/ssh package that allows an attacker to bypass certificate-based restrictions in SSH connections. This could permit unauthorised access to systems that rely on SSH certificate validation as a security control. Services and applications built on Go that use this library for SSH communication — including Azure-hosted workloads — may be affected.

Architect’s Take: Audit any Go-based services deployed in your Azure environment that use golang.org/x/crypto/ssh for SSH connectivity, and update to the patched version of the library as soon as it is available. Pay particular attention to internal tooling, CI/CD pipelines, and infrastructure automation that may authenticate via SSH certificates.

Original advisory: CVE-2026-39828 Invoking bypass of certificate restrictions in golang.org/x/crypto/ssh