CVE-2026-90616In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulner…

In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925. Flatpak creates a few app data directories (e.g., /var/cache, /var/data, /var/config, and /var/tmp) in every sandbox on every app launch where, in some cases, components of the path are attacker-controlled. Missing symlink protection can redirect the directories. Some of these directories are bind-mounted by Flatpak by passing the path (e.g., /home/user/.var/app/APP_ID/cache/tmp), which contains attacker-controlled directories (tmp) to bwrap --bind SRC DST. bwrap passes the path on to the kernel, which then follows symlinks. A malicious symlink can point to arbitrary locations on the host and it will become mounted inside the sandbox.

CVSS

7.4 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness (CWE)

CWE-61

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

mitre

NVD analysis

Awaiting Analysis

Record last updated

Sep 14, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.