CVE-2026-41525: KDE Dolphin Path Traversal Vulnerability

CVE-2026-41525 Overview

CVE-2026-41525 is a sandbox escape vulnerability in KDE Dolphin file manager before version 25.12.3. The vulnerability exists in Dolphin's implementation of the FileManager1 protocol, which allows applications running in a Flatpak sandbox or under AppArmor confinement to open folders outside of the application sandbox without additional scrutiny. More critically, the protocol allows the path given to be any type of file, including scripts or executables, potentially enabling malicious applications to bypass sandbox restrictions.

Critical Impact
Sandboxed applications can potentially escape confinement and execute arbitrary scripts or executables on the host system by exploiting the FileManager1 protocol implementation in KDE Dolphin.

Affected Products

KDE Dolphin versions prior to 25.12.3
Systems using Flatpak-based sandboxed applications with Dolphin as the default file manager
Systems using AppArmor-confined applications with Dolphin as the default file manager

Discovery Timeline

2026-04-28 - CVE-2026-41525 published to NVD
2026-04-28 - Last updated in NVD database

Technical Details for CVE-2026-41525

Vulnerability Analysis

This vulnerability is classified under CWE-669 (Incorrect Resource Transfer Between Spheres), which indicates a fundamental flaw in how Dolphin handles resource transfers across security boundaries. The issue centers on the FileManager1 D-Bus protocol implementation, which is designed to allow sandboxed applications to request that the system file manager display specific folders. However, Dolphin's implementation fails to properly validate that the requested path is actually a folder and doesn't adequately restrict access to paths outside the sandbox.

When a sandboxed application sends a request via the FileManager1 interface, Dolphin accepts any file path without proper scrutiny. If the path points to an executable or script, Dolphin's default behavior is to display a consent prompt asking the user if they want to execute the file. However, this behavior itself represents a security failure—the intended security model should block such requests outright rather than deferring to user judgment, as users may not understand the security implications of the prompt.

Root Cause

The root cause lies in insufficient input validation within Dolphin's FileManager1 protocol handler. The implementation does not differentiate between directory paths and executable file paths, nor does it verify that requested paths fall within the sandbox boundaries of the requesting application. This design flaw violates the principle of sandbox isolation by allowing contained applications to interact with arbitrary filesystem locations through the file manager.

Attack Vector

This is a local attack vector requiring user interaction. An attacker must first have a malicious application installed within a Flatpak or AppArmor sandbox on the target system. The attack flow proceeds as follows:

The malicious sandboxed application sends a D-Bus message to Dolphin via the FileManager1 interface
The message contains a path to a script or executable outside the sandbox (potentially attacker-controlled or a system binary)
Dolphin receives the request and, rather than blocking it, opens the file location or presents an execution prompt
If the user accepts the prompt (or if Dolphin is configured to auto-execute certain file types), the code executes outside the sandbox context

The vulnerability is notable because it undermines the trust users place in sandbox technologies like Flatpak and AppArmor, which are specifically designed to prevent applications from accessing resources outside their designated boundaries.

Detection Methods for CVE-2026-41525

Indicators of Compromise

Unexpected D-Bus messages to the org.freedesktop.FileManager1 interface originating from sandboxed applications
Dolphin file manager opening paths to executables or scripts outside of expected sandbox directories
Execution of scripts or binaries from unexpected locations shortly after Flatpak application activity
System logs showing FileManager1 protocol requests for sensitive system paths (e.g., /usr/bin/, /home/*/scripts/)

Detection Strategies

Monitor D-Bus traffic for FileManager1 interface calls that reference executable files or paths outside typical user document directories
Implement logging for Dolphin's file opening operations, particularly when triggered by external D-Bus requests
Deploy endpoint detection rules that alert on sandboxed applications initiating file manager operations on executable content
Review Flatpak application permissions and D-Bus access policies for unnecessary FileManager1 access

Monitoring Recommendations

Enable audit logging for D-Bus communications, specifically the org.freedesktop.FileManager1 interface
Configure SentinelOne to monitor for unusual parent-child process relationships where Dolphin launches executables after receiving D-Bus requests
Implement file integrity monitoring for directories commonly targeted in sandbox escape attacks
Correlate Flatpak application activity with subsequent privileged file operations

How to Mitigate CVE-2026-41525

Immediate Actions Required

Upgrade KDE Dolphin to version 25.12.3 or later immediately
Review installed Flatpak applications and remove any untrusted or unnecessary applications
Consider temporarily using an alternative file manager for systems that cannot be immediately patched
Audit D-Bus policies to restrict FileManager1 access from sandboxed applications where not required

Patch Information

KDE has released version 25.12.3 of Dolphin which addresses this vulnerability. The patch modifies the FileManager1 protocol handler to properly validate that requested paths are directories and fall within acceptable boundaries for sandboxed applications. Users should update through their distribution's package manager or directly from the KDE Dolphin Release Notes. Additional technical details are available in the KDE Security Advisory 20260427-2.

Workarounds

Restrict D-Bus access to the FileManager1 interface for sandboxed applications by modifying Flatpak permissions
Configure Dolphin to never execute scripts or executables regardless of user consent prompts
Use AppArmor or SELinux profiles to limit Dolphin's ability to execute files opened via D-Bus requests
Consider disabling automatic file manager invocation from Flatpak applications until patching is complete

For environments where immediate patching is not possible, administrators can implement D-Bus filtering policies to restrict which applications can communicate with the FileManager1 interface. This can be configured through Flatpak permissions by denying the --filesystem and --talk-name=org.freedesktop.FileManager1 permissions for untrusted applications.