CVE-2026-49957: nesquena Hermes WebUI workspace boundary bypass in remote terminal resolution

CVE-2026-49957 · Severity: high · CVSS 7.7 · Published 2026-06-09

Hermes WebUI, a web-based interface for managing remote terminals and workspaces, contains a security flaw that allows users to bypass directory restrictions. By manipulating remote terminal settings, an authenticated user can trick the system into granting access to sensitive local server files, such as system configuration files. This could lead to the exposure of confidential system data and credentials, potentially compromising the entire server hosting the application.

Technologies: Nesquena Hermes WebUI. Vendors: Nesquena.

Quick answers

Is CVE-2026-49957 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-49957 being exploited in the wild.
How severe is CVE-2026-49957?
High severity, with a CVSS score of 7.7, published 9 June 2026.
Which products and versions are affected?
Nesquena Hermes WebUI < 0.51.269.
Is there a fix for CVE-2026-49957?
A patch was published on 2026-06-06: Fix merged in GitHub PR #3744 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-49957 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-49957?
Check whether you run Nesquena Hermes WebUI at an affected version. 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 path traversal and boundary bypass vulnerability exists in Hermes WebUI's workspace resolution logic. The function `_remote_terminal_workspace_candidate()` contained an early return that accepted paths under a configured remote terminal's current working directory (CWD) before the `_is_blocked_workspace_path()` security guard could execute. An authenticated attacker can configure a remote terminal profile with a CWD pointing to a sensitive system directory (e.g., `/etc`). When the application resolves this workspace, it treats the system directory as a trusted local workspace root. Consequently, workspace file-read helpers, which operate on local paths, can be used to retrieve arbitrary files from the host operating system. The vulnerability is addressed in version 0.51.269 by ensuring blocked-root checks are performed on both the candidate path and the base CWD path before acceptance.

Affected products

  • nesquena Hermes WebUI < 0.51.269

Timeline

  • 2026-06-06: patched: Fix merged in GitHub PR #3744
  • 2026-06-09: disclosed: CVE-2026-49957 published

References

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