Ubuntu 26.04 LTS mailcap Critical Remote Code Execution USN-8518-1

ubuntu

July 8, 2026

mailcap could allow applications to escape sandbox restrictions

Summary

mailcap could allow applications to escape sandbox restrictions

Software Description:

- mailcap: Debian's mailcap system, and support programs

Details:

Aaron Rainbolt discovered that the cautious-launcher utility in the

mailcap package did not properly restrict the execution of certain

file types. An attacker could use this issue to escape a sandboxed

application and execute arbitrary code on the host operating system.

Topics Covered

security advisory remote code execution Ubuntu sandbox escape mailcap CVE-2026-10037

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 26.04 LTS
  mailcap                         3.75ubuntu1.1

Ubuntu 25.10
  mailcap                         3.74ubuntu1.1

Ubuntu 24.04 LTS
  mailcap                         3.70+nmu1ubuntu1.24.04.1

Ubuntu 22.04 LTS
  mailcap                         3.70+nmu1ubuntu1.22.04.1

In general, a standard system update will make all the necessary changes.