A malicious Git server can advertise a bundle URI that, when a Windows user clones or fetches with transfer.bundleuri enabled, triggers Git for Windows to treat the URI as a local filesystem path. The resulting build of the path is used to copy the bundle to the local file system, which causes Windows to resolve a UNC or file:// path as a network share and open an outbound SMB connection. The SMB authentication performed by Windows sends NTLM credentials to the attacker-controlled host, thus exposing an authentication mechanism that the attacker can harvest.

Any installation of Git for Windows prior to version 2.55.0.windows.4 that processes server‑advertised bundle URIs is vulnerable. The CVE affects the git-for-windows:git product when the transfer.bundleuri feature is enabled.

The CVSS score of 7.4 indicates a high‑severity flaw. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog, but the exploitation path is realistic: a remote Git server can supply a crafted bundle URI and trigger an SMB callback without further authentication. Because the SMB connection carries NTLM tokens, the impact includes the disclosure of authentication credentials. The vulnerability requires the user’s Windows account to be used to initiate the SMB connection, so users with higher privileges are particularly at risk.