CVE-2026-96281
Flatpak: flatpak: unprivileged active user can bypass anti-downgrade checks for system apps/runtimes
What happened?
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.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| flatpakRed Hat | Default status: affected | See vendor advisory |
| flatpakRed Hat | Default status: affected | See vendor advisory |
| flatpakRed Hat | Default status: affected | See vendor advisory |
| flatpakRed Hat | Default status: affected | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.