# CVE-2026-10037: mailcap: A sandbox escape vulnerability exists in the OpenJDK packages provided in Ubuntu

CVE-2026-10037 is fixed in mailcap on 1 platform, first by mailcap 3.75ubuntu1.1, released July 8, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-10037
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 8, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | mailcap Ubuntu 22.04.1 LTS (jammy) | 3.70+nmu1ubuntu1.22.04.1 | [mailcap 3.70+nmu1ubuntu1.22.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-mailcap-3.70-nmu1ubuntu1.22.04.1.md) | Jul 9, 2026 |
| Linux | mailcap Ubuntu 24.04.5 LTS (noble) | 3.70+nmu1ubuntu1.24.04.1 | [mailcap 3.70+nmu1ubuntu1.24.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-mailcap-3.70-nmu1ubuntu1.24.04.1.md) | Jul 9, 2026 |
| Linux | mailcap Ubuntu 25.10 (questing) | 3.74ubuntu1.1 | [mailcap 3.74ubuntu1.1](https://patchblox.com/security/data/fix/linux/ubuntu-questing-mailcap-3.74ubuntu1.1.md) | Jul 9, 2026 |
| Linux | mailcap Ubuntu 26.04.1 LTS (resolute) | 3.75ubuntu1.1 | [mailcap 3.75ubuntu1.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-mailcap-3.75ubuntu1.1.md) | Jul 8, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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