# CVE-2026-96281: Flatpak: flatpak: unprivileged active user can bypass anti-downgrade checks for system apps/runtimes

> A local user can bypass anti-downgrade protections to install vulnerable older versions of system-wide Flatpak applications.

- **Severity:** Medium 6.2 (`CVSS:3.1/AV:P/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 27 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-96281, UBUNTU-CVE-2026-96281

## What is CVE-2026-96281?

CVE-2026-96281 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 27 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

On a multi-user system, a user with an active local login session could downgrade a system-wide Flatpak app to an older version by removing the app's remote ref via the unprivileged system-helper RemoveLocalRef method, causing the anti-downgrade check to fail to find a reference date. A malicious local user could use this to expose other users of the same system to an app version with unfixed vulnerabilities.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-96281?


## How do I fix CVE-2026-96281?

Apply the vendor's patch.

## Is CVE-2026-96281 being exploited?

There is no known exploitation of CVE-2026-96281 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-96281 and fix it if it is affected.

What it is: CVE-2026-96281 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 27 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-2026-96281 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-2026-96281/ (Markdown: https://insights.sbomify.com/CVE-2026-96281/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-96281
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96281
- OSV: https://osv.dev/vulnerability/CVE-2026-96281

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-96281/
Summaries are generated and may contain mistakes; the official description above is the record.