---
id: CVE-2026-90616
title: >-
  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
summary: >-
  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 c…
severity: high
cvss: 7.4
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-61
  - CWE-59
vendor: Flatpak
product: Flatpak
affected:
  - Flatpak < 1.18.1
published: '2026-09-12'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T19:56:19.073'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90616'
references:
  - url: 'https://github.com/flatpak/flatpak/security/advisories/GHSA-8688-9x26-hhxj'
    label: cve@mitre.org
  - url: 'https://www.openwall.com/lists/oss-security/2026/08/11/9'
    label: cve@mitre.org
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90616.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-90616'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532613'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-90616'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90616'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00181
epssPercentile: 0.06773
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-14T18:22:12.062132Z'
scores:
  nvd: 7.4
  cna: 7.4
  vendor: 7.8
ingestedAt: '2026-09-14T15:23:07.478Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90616.json)