CVE-2026-49959 Hermes WebUI < 0.51.311 RCE via Git Configuration Injection
Authenticated attackers can execute arbitrary commands on the host by injecting malicious Git configurations into workspace repositories.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-49959?
CVE-2026-49959 is a high-severity command injection vulnerability in nesquena hermes-webui, published on 9 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Hermes WebUI before version 0.51.311 contains a remote code execution vulnerability that allows authenticated attackers to execute arbitrary commands by placing malicious executable Git configuration in a workspace repository's .git/config file. Attackers can exploit Git subprocess invocations in api/workspace_git.py through vectors such as core.fsmonitor during git status, protocol.ext.allow with ext:: remotes during git fetch, credential.helper, core.askPass, core.gitProxy, or inherited environment variables including GIT_SSH_COMMAND to achieve arbitrary command execution on the host running the application.
Weakness: CWE-78
Which versions are affected by CVE-2026-49959?
How do I fix CVE-2026-49959?
No fix has been published for CVE-2026-49959 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-49959 being exploited?
There is no known exploitation of CVE-2026-49959 in the wild and no public exploit code.
Sources
Also known as GHSA-69x8-4j5h-mmr4.