# CVE-2026-84828: Pcs: pcs: non-root haclient users can read arbitrary files via pcs host auth --token

> Local attackers in the haclient group can read arbitrary short files via the pcs host auth command, exposing sensitive data like API keys.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-84828, GHSA-5g5g-4cqv-r2jw, UBUNTU-CVE-2026-84828

## What is CVE-2026-84828?

CVE-2026-84828 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 10 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw was found in PCS (Pacemaker Configuration System). A local attacker with membership in the 'haclient' group can exploit the 'pcs host auth --token' command to read the contents of arbitrary files on the filesystem, provided the files are shorter than 256 bytes. The file contents are read with root privileges by the pcsd daemon and can be exfiltrated by the attacker through subsequent cluster node communication. This allows disclosure of sensitive data such as API keys, tokens, or configuration secrets that would otherwise be inaccessible to the attacker.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource)

## Which versions are affected by CVE-2026-84828?


## How do I fix CVE-2026-84828?

Apply the vendor's patch.

## Is CVE-2026-84828 being exploited?

There is no known exploitation of CVE-2026-84828 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-84828 and fix it if it is affected.

What it is: CVE-2026-84828 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 10 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-84828 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. 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-2026-84828/ (Markdown: https://insights.sbomify.com/CVE-2026-84828/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-84828
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-84828
- OSV: https://osv.dev/vulnerability/CVE-2026-84828

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-84828/
Summaries are generated and may contain mistakes; the official description above is the record.