Ubuntu 26.04 libslirp Important Info Exposure CVE-2026-9539 Advisory 8550-1

ubuntu

July 15, 2026

libslirp could be made to expose sensitive information over the network.

Summary

libslirp could be made to expose sensitive information over the network.

Software Description:

- libslirp: General purpose TCP-IP emulator library

Details:

It was discovered that libslirp incorrectly handled TCP urgent data. A

privileged attacker inside a guest VM could possibly use this issue to

obtain sensitive information from the host process memory.

Topics Covered

security advisory Ubuntu important information exposure libslirp guest vm attack

Update Instructions

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

Ubuntu 26.04 LTS
  libslirp0                       4.9.1-1ubuntu1.1

Ubuntu 24.04 LTS
  libslirp0                       4.7.0-1ubuntu3.1

Ubuntu 22.04 LTS
  libslirp0                       4.6.1-1ubuntu0.2

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