Git refuses non-HTTP bundle URIs after Windows NTLM leak

Git will no longer fetch server-advertised bundle URIs unless they pass the usual protocol allow-list, closing a Windows-only credential leak tracked as CVE-2026-62960.

A malicious or compromised remote could advertise a bundle location that was not HTTP or HTTPS. Git treated that advertisement as a local path. On Windows, a UNC-style path could trigger an outbound SMB connection and, because of transparent NTLM authentication, hand the user’s credentials to an attacker-controlled share during clone or fetch.

Johannes Schindelin’s fix applies the existing protocol.*.allow rules to advertised bundle URIs on the clone and fetch path. File and bare paths are denied by default; http, https, git, and ssh remain permitted. Each skipped URI is reported. Explicit user-supplied --bundle-uri values are unchanged, and administrators can still opt back into advertised file URIs with protocol.file.allow=always. Listing via ls-remote is unaffected.

The flaw matters only on Windows. The change shipped in Git for Windows v2.55.0(4).