10.0
CRITICAL CVSS 3.1
CVE-2026-34078
Flatpak has a complete sandbox escape leading to host file access and code execution in the host context
Description

Flatpak is a Linux application sandboxing and distribution framework. Prior to 1.16.4, the Flatpak portal accepts paths in the sandbox-expose options which can be app-controlled symlinks pointing at arbitrary paths. Flatpak run mounts the resolved host path in the sandbox. This gives apps access to all host files and can be used as a primitive to gain code execution in the host context. This vulnerability is fixed in 1.16.4.

INFO

Published Date :

April 7, 2026, 10:16 p.m.

Last Modified :

April 24, 2026, 5:50 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-34078 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Flatpak flatpak
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL [email protected]
Solution
Update Flatpak to version 1.16.4 or later to address symlink vulnerabilities.
  • Update Flatpak to 1.16.4 or a later version.
  • Apply vendor-provided patches for Flatpak.
  • Review sandbox configurations for exposed paths.
Public PoC/Exploit Available at Github

CVE-2026-34078 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-34078.

URL Resource
https://github.com/flatpak/flatpak/security/advisories/GHSA-cc2q-qc34-jprg Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/09/8 Third Party Advisory Mailing List
http://www.openwall.com/lists/oss-security/2026/04/10/14 Mailing List Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-34078 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-34078 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

DSA and DLA for Debian last 14 days

Python

Updated: 5 days, 14 hours ago
0 stars 0 fork 0 watcher
Born at : Feb. 12, 2025, 2:08 p.m. This repo has been linked 116 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-34078 vulnerability anywhere in the article.

  • Help Net Security
Tails 7.6.2 patches vulnerability that could expose saved files

The Tails Project released Tails v7.6.2, an emergency release of the popular open source secure portable operating system. What is Tails? Tails, which is based on Debian GNU/Linux, is aimed at users w ... Read more

Published Date: Apr 16, 2026 (2 weeks ago)
  • The Hacker News
⚡ Weekly Recap: Fiber Optic Spying, Windows Rootkit, AI Vulnerability Hunting and More

Monday is back, and the weekend’s backlog of chaos is officially hitting the fan. We are tracking a critical zero-day that has been quietly living in your PDFs for months, plus some aggressive state-s ... Read more

Published Date: Apr 13, 2026 (2 weeks, 3 days ago)
  • Help Net Security
Week in review: Windows zero-day exploit leaked, Patch Tuesday forecast

Here’s an overview of some of last week’s most interesting news, articles, interviews and videos: Cloudflare moves up its post-quantum deadline as researchers narrow the path to Q-Day Cloudflare annou ... Read more

Published Date: Apr 12, 2026 (2 weeks, 4 days ago)
  • Daily CyberSecurity
Root Access at Risk: Critical Nix Sandbox Escape Overwrites Sensitive System Files

A severe security vulnerability has been identified in the Nix package manager, a tool celebrated by the Linux and Unix communities for making package management reliable and reproducible. Tracked as ... Read more

Published Date: Apr 10, 2026 (2 weeks, 6 days ago)
  • Daily CyberSecurity
Denial of Service Alert: React Server Components Vulnerability Causes CPU Spikes

React, the popular JavaScript library used by millions of developers for building user interfaces, has issued an urgent advisory regarding a denial of service (DoS) vulnerability. The flaw specificall ... Read more

Published Date: Apr 09, 2026 (3 weeks ago)
  • Daily CyberSecurity
Sandbox Escape: Critical Flatpak Flaw Grants Full Host Access

Flatpak, the widely-used system for building, distributing, and running sandboxed desktop applications on Linux, has been hit by a critical security vulnerability. The flaw, tracked as CVE-2026-34078 ... Read more

Published Date: Apr 09, 2026 (3 weeks ago)
  • Help Net Security
Flatpak 1.16.4 fixes sandbox escape and three other security flaws

Flatpak, a Linux application sandboxing and distribution framework, released version 1.16.4, patching four security vulnerabilities. The most severe fix addresses a complete sandbox escape that leads ... Read more

Published Date: Apr 08, 2026 (3 weeks, 1 day ago)

The following table lists the changes that have been made to the CVE-2026-34078 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Apr. 24, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
    Added CPE Configuration OR *cpe:2.3:a:flatpak:flatpak:*:*:*:*:*:*:*:* versions up to (including) 1.16.3
    Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/04/09/8 Types: Mailing List, Third Party Advisory
    Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/04/10/14 Types: Mailing List, Third Party Advisory
    Added Reference Type GitHub, Inc.: https://github.com/flatpak/flatpak/security/advisories/GHSA-cc2q-qc34-jprg Types: Vendor Advisory
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Apr. 11, 2026

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2026/04/10/14
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Apr. 09, 2026

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2026/04/09/8
  • New CVE Received by [email protected]

    Apr. 07, 2026

    Action Type Old Value New Value
    Added Description Flatpak is a Linux application sandboxing and distribution framework. Prior to 1.16.4, the Flatpak portal accepts paths in the sandbox-expose options which can be app-controlled symlinks pointing at arbitrary paths. Flatpak run mounts the resolved host path in the sandbox. This gives apps access to all host files and can be used as a primitive to gain code execution in the host context. This vulnerability is fixed in 1.16.4.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-61
    Added Reference https://github.com/flatpak/flatpak/security/advisories/GHSA-cc2q-qc34-jprg
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.