# CVE-2026-49957: Hermes WebUI < 0.51.296 Workspace Boundary Bypass via api/workspace.py

> Authenticated attackers can bypass workspace restrictions to read local system files by manipulating remote terminal working directory settings.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Jun 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-5cwx-phm8-m83r

## What is CVE-2026-49957?

CVE-2026-49957 is a medium-severity path traversal 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 0.51.296 contains a workspace boundary bypass vulnerability that allows authenticated attackers to circumvent blocked-root path checks by exploiting an early return in the SSH/remote terminal profile workspace resolution logic within _remote_terminal_workspace_candidate(). Attackers can configure a remote terminal working directory to a system directory such as /etc, causing the workspace resolution path to accept it as a trusted local workspace root before the _is_blocked_workspace_path() guard executes, enabling read access to local system files through workspace file-read helpers.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-49957?


## How do I fix CVE-2026-49957?

No fix has been published for CVE-2026-49957 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-49957 being exploited?

There is no known exploitation of CVE-2026-49957 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-49957 and fix it if it is affected.

What it is: CVE-2026-49957 is a medium-severity path traversal 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.
Exploitation: There is no known exploitation of CVE-2026-49957 in the wild and no public exploit code.

Affected product: nesquena hermes-webui. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-49957/ (Markdown: https://insights.sbomify.com/CVE-2026-49957/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49957
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49957
- OSV: https://osv.dev/vulnerability/CVE-2026-49957

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-49957/
Summaries are generated and may contain mistakes; the official description above is the record.