Key Exchange without Entity Authentication Affecting dulwich package, versions [,1.1.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-DULWICH-18016337
- published19 Jul 2026
- disclosed15 Jul 2026
- creditUnknown
Introduced: 15 Jul 2026
NewCVE-2026-38974 (opens in a new tab)How to fix?
Upgrade dulwich to version 1.1.0 or higher.
Overview
Affected versions of this package are vulnerable to Key Exchange without Entity Authentication through contrib/paramiko_vendor.py in the SSH connection path. An attacker can intercept or impersonate an SSH server and have the client connect without validating the server’s host key by supplying a malicious host during a Git-over-SSH operation. This allows man-in-the-middle attacks against SSH-based Git access, exposing repository data and credentials in transit and letting the attacker tamper with fetched or pushed content.
Notes
- Affected SSH sessions also honor
GlobalKnownHostsFileandUserKnownHostsFileentries from the local SSH config when present; deployments that rely on those paths for trust material are part of the verification path. - The vulnerable behavior applies in the vendor’s default SSH client setup, which accepted unknown host keys instead of enforcing any known-hosts policy before
client.connect(...).