Vulnerability · Published Sep 27, 2026 · Assigned by redhat
CVE-2026-96281Flatpak: flatpak: unprivileged active user can bypass anti-downgrade checks for system apps/runtimes
Medium 6.2
In plain English
A medium-severity improper access control in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | flatpak | no fix listed | DEBIAN-CVE-2026-96281 |
| Debian:13 | flatpak | 1.16.6-1~deb13u2 | DEBIAN-CVE-2026-96281 |
| Debian:14 | flatpak | 1.18.1-1 | DEBIAN-CVE-2026-96281 |
| Ubuntu:26.04:LTS | flatpak | no fix listed | UBUNTU-CVE-2026-96281 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
Weakness: CWE-284 · Vector: CVSS:3.1/AV:P/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
References
- https://access.redhat.com/security/cve/CVE-2026-96281 vdb-entry, x_refsource_REDHAT
- RHBZ#2539421 issue-tracking, x_refsource_REDHAT
- https://github.com/flatpak/flatpak/security/advisories/GHSA-q4gr-vc25-57m5