# CVE-2026-49959: nesquena Hermes WebUI remote code execution via Git configuration injection

Source: https://junglewise.ai/threats/cve-2026-49959-nesquena-hermes-webui-remote-code-execution-via-git-configuration  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-09. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-49959 · Severity: high · CVSS 8.8 · Published 2026-06-09

Hermes WebUI, a management interface for workspace repositories, is vulnerable to a security flaw that allows users to take control of the underlying server. By uploading or restoring a repository with a specially crafted configuration file, an attacker can force the system to run malicious commands during routine operations like checking repository status. This could lead to a total compromise of the application server and any data stored within it.

## Quick answers

**Is CVE-2026-49959 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-49959 being exploited in the wild.

**How severe is CVE-2026-49959?** High severity, with a CVSS score of 8.8, published 9 June 2026.

**Which products and versions are affected?** nesquena Hermes WebUI < 0.51.311.

**Is there a fix for CVE-2026-49959?** A patch was published on 2026-06-07: Fix included in release v0.51.311 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-49959 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-49959?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A remote code execution (RCE) vulnerability exists in Hermes WebUI due to improper neutralization of Git configuration settings in workspace repositories. Authenticated attackers can inject malicious executable directives into a repository's .git/config file. When the application invokes Git subprocesses via api/workspace_git.py (such as during 'git status' or 'git fetch'), it may trigger these directives through vectors including core.fsmonitor, credential.helper, core.askPass, or protocol.ext.allow. The vulnerability also extends to inherited environment variables like GIT_SSH_COMMAND. This allows for arbitrary command execution on the host with the privileges of the application process. The issue is fixed in version 0.51.311 by enforcing hardened Git configuration overrides (-c) and scrubbing sensitive environment variables.

## Affected products

- nesquena Hermes WebUI < 0.51.311

## Timeline

- 2026-06-07: patched: Fix included in release v0.51.311
- 2026-06-09: disclosed: CVE published to NVD

## References

- [https://github.com/nesquena/hermes-webui/commit/938ac9f55b53def1eefb48c4c42dabaf9c22e99c](https://github.com/nesquena/hermes-webui/commit/938ac9f55b53def1eefb48c4c42dabaf9c22e99c)
- [https://github.com/nesquena/hermes-webui/pull/3776](https://github.com/nesquena/hermes-webui/pull/3776)
- [https://github.com/nesquena/hermes-webui/releases/tag/v0.51.311](https://github.com/nesquena/hermes-webui/releases/tag/v0.51.311)
- [https://www.vulncheck.com/advisories/hermes-webui-rce-via-git-configuration-injection](https://www.vulncheck.com/advisories/hermes-webui-rce-via-git-configuration-injection)