Sandbox Escape in OpenJDK via Mailcap MIME Handlers

Publication date: 2026-07-08

Last updated on: 2026-07-08

Assigner: Canonical Ltd.

Description

A sandbox escape vulnerability exists in the OpenJDK packages provided in Ubuntu. The .jar MIME handlers installed by these packages execute files marked as executable when the mailcap package is installed. A compromised or malicious sandboxed application with access to the OpenURI portal via xdg-desktop-portal-gtk can write a malicious .jar file to the host file system, set its executable bit, and trigger the handler to execute arbitrary code outside of the sandbox environment.

CVSS Scores

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Meta Information

Published

2026-07-08

Last Modified

2026-07-08

Generated

2026-07-09

AI Q&A

2026-07-09

EPSS Evaluated

N/A

NVD

CVE-2026-10037

Affected Vendors & Products

Vendor	Product	Version / Range
ubuntu	openjdk	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-20	The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Attack-Flow Graph

Executive Summary

This vulnerability is a sandbox escape issue found in the OpenJDK packages provided by Ubuntu. It involves the .jar MIME handlers that execute files marked as executable when the mailcap package is installed. A malicious or compromised sandboxed application that can access the OpenURI portal via xdg-desktop-portal-gtk can write a harmful .jar file to the host system, set it as executable, and cause the handler to run arbitrary code outside the sandbox.

Impact Analysis

This vulnerability can allow an attacker to execute arbitrary code outside of the sandbox environment, potentially leading to full system compromise. Because the attacker can run code with the privileges of the user, this can result in unauthorized access, data theft, or disruption of system operations.

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