Git for Windows: Server-advertised bundle-uri can trigger outbound SMB callbacks via UNC and file:// paths on Windows
Published Aug 21, 2026 · Updated Nov 3, 2026
Original summary
Normalized public record · Updated Nov 3, 2026
Git for Windows: Server-advertised bundle-uri can trigger outbound SMB callbacks via UNC and file:// paths on Windows
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
Git for Windows is the Windows port of Git. Prior to 2.55.0.windows.4, a malicious remote Git server can advertise a bundle URI that reaches transport_get_remote_bundle_uri(), fetch_bundle_uri_internal(), and copy_uri_to_file() in bundle-uri.c during clone or fetch when transfer.bundleuri=true. Non-HTTP(S) values are treated as local filesystem paths, and file URI prefixes are removed, so a bare UNC path or file URI targeting an attacker-controlled share causes Windows to initiate an outbound SMB connection. This can expose NTLM authentication material to the attacker-selected host. This issue is fixed in version 2.55.0.windows.4.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- MEDIUM
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Aug 21, 2026 · Last refreshed Nov 3, 2026