# CVE-2026-21785: HCL BigFix Remote Control Server WebUI is affected by a misconfigured Content Security Policy

> Attackers can bypass Content Security Policy restrictions to load unauthorized resources in HCL BigFix Remote Control Server WebUI.

- **Severity:** Medium 4.0 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 27 May 2026
- **Updated:** 28 May 2026
- **Also known as:** GHSA-6x6f-pfq2-m75m

## What is CVE-2026-21785?

CVE-2026-21785 is a medium-severity vulnerability in HCLSoftware BigFix Remote Control Server, published on 27 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

A misconfigured Content Security Policy (CSP) in HCL BigFix Remote Control Server WebUI (versions 10.1.0.0442 and earlier) fails to define directives without fallbacks, allowing attackers to bypass intended security restrictions and load unauthorized resources.

Weakness: CWE-1021 (Improper Restriction of Rendered UI Layers or Frames)

## Which versions are affected by CVE-2026-21785?


## How do I fix CVE-2026-21785?

No fix has been published for CVE-2026-21785 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-21785 being exploited?

There is no known exploitation of CVE-2026-21785 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21785 and fix it if it is affected.

What it is: CVE-2026-21785 is a medium-severity vulnerability in HCLSoftware BigFix Remote Control Server, published on 27 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-21785 in the wild and no public exploit code.

Affected product: HCLSoftware BigFix Remote Control Server. 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-2026-21785/ (Markdown: https://insights.sbomify.com/CVE-2026-21785/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21785
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21785
- OSV: https://osv.dev/vulnerability/CVE-2026-21785

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-21785/
Summaries are generated and may contain mistakes; the official description above is the record.