# CVE-2026-84838: Rpm: command injection in rpmuncompress via unescaped filenames passed to popen()

> Local attackers can execute arbitrary commands via crafted archive filenames in rpmuncompress, requiring user interaction to trigger.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 2 Sep 2026
- **Updated:** 14 Oct 2026
- **Also known as:** AZL-99372, DEBIAN-CVE-2026-84838, ECHO-f52f-43fd-e847, GHSA-h54x-hjr5-ww2x, UBUNTU-CVE-2026-84838

## What is CVE-2026-84838?

CVE-2026-84838 is a high-severity command injection vulnerability in Red Hat Enterprise Linux 10, published on 2 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A flaw was found in rpmuncompress. This command injection vulnerability allows a local attacker to execute arbitrary commands. This occurs when rpmuncompress processes a specially crafted archive filename containing shell metacharacters, which are not properly escaped before being passed to shell command strings. Successful exploitation requires user interaction, where a user or automated workflow invokes rpmuncompress on the malicious file, leading to high impact on the confidentiality, integrity, and availability of data accessible to the invoking user.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-84838?


## How do I fix CVE-2026-84838?

Apply the vendor's patch.

## Is CVE-2026-84838 being exploited?

There is no known exploitation of CVE-2026-84838 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-84838 and fix it if it is affected.

What it is: CVE-2026-84838 is a high-severity command injection vulnerability in Red Hat Enterprise Linux 10, published on 2 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-84838 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-2026-84838/ (Markdown: https://insights.sbomify.com/CVE-2026-84838/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-84838
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-84838
- OSV: https://osv.dev/vulnerability/CVE-2026-84838

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-84838/
Summaries are generated and may contain mistakes; the official description above is the record.