Vulnerability · Published Jul 8, 2026 · Assigned by canonical

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

High 8.8

In plain English

A high-severity improper input validation in Ubuntu from Canonical. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.2%top 92.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Ubuntu:22.04:LTSmailcap3.70+nmu1ubuntu1.22.04.1UBUNTU-CVE-2026-10037
Ubuntu:24.04:LTSmailcap3.70+nmu1ubuntu1.24.04.1UBUNTU-CVE-2026-10037
Ubuntu:25.10mailcap3.74ubuntu1.1UBUNTU-CVE-2026-10037
Ubuntu:26.04:LTSmailcap3.75ubuntu1.1UBUNTU-CVE-2026-10037
Ubuntu:26.10mailcapno fix listedUBUNTU-CVE-2026-10037
Ubuntu:26.10openjdk-17no fix listedUBUNTU-CVE-2026-10037
Ubuntu:26.10openjdk-17-cracno fix listedUBUNTU-CVE-2026-10037
Ubuntu:22.04:LTSopenjdk-18no fix listedUBUNTU-CVE-2026-10037
Ubuntu:26.10openjdk-21no fix listedUBUNTU-CVE-2026-10037
Ubuntu:26.10openjdk-21-cracno fix listedUBUNTU-CVE-2026-10037
Ubuntu:26.10openjdk-8no fix listedUBUNTU-CVE-2026-10037
Ubuntu:26.10openjdk-ltsno fix listedUBUNTU-CVE-2026-10037

Affected products (as reported)

VendorProductVersions
Canonical Ubuntu see references
Canonical Ubuntu see references
Canonical Ubuntu see references
Canonical Ubuntu see references
Canonical Ubuntu see references
Canonical Ubuntu see references
Canonical Ubuntu see references
Canonical Ubuntu see references
Canonical Ubuntu see references
Canonical Ubuntu 0 – before 3.70+nmu1ubuntu1.22.04.10 – before 3.70+nmu1ubuntu1.24.04.10 – before 3.74ubuntu1.10 – before 3.75ubuntu1.1

Weakness: CWE-20 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References