[USN-8360-1] sslh vulnerability

[noreply+usn-bot at canonical.com]

==========================================================================
Ubuntu Security Notice USN-8360-1
June 01, 2026

sslh vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 26.04 LTS
- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

sslh could be made to overwrite files.

Software Description:
- sslh: Applicative protocol multiplexer

Details:

It was discovered that sslh did not properly handle symbolic
links when writing its PID file. A local attacker could
possibly use this issue to overwrite arbitrary files.

Update instructions:

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

Ubuntu 26.04 LTS
  sslh                            2.1.4-1ubuntu0.26.04.1

Ubuntu 25.10
  sslh                            2.1.4-1ubuntu0.25.10.1

Ubuntu 24.04 LTS
  sslh                            1.22c-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro

Ubuntu 22.04 LTS
  sslh                            1.20-1+deb11u1build0.22.04.1

Ubuntu 20.04 LTS
  sslh                            1.20-1+deb11u1build0.20.04.1
                                  Available with Ubuntu Pro

Ubuntu 18.04 LTS
  sslh                            1.18-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  sslh                            1.17-2ubuntu0.1~esm1
                                  Available with Ubuntu Pro

After a standard system update you need to restart sslh to
make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-8360-1
  CVE-2025-52936

Package Information:
  https://launchpad.net/ubuntu/+source/sslh/2.1.4-1ubuntu0.26.04.1
  https://launchpad.net/ubuntu/+source/sslh/2.1.4-1ubuntu0.25.10.1
  https://launchpad.net/ubuntu/+source/sslh/1.20-1+deb11u1build0.22.04.1
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <https://lists.ubuntu.com/archives/ubuntu-security-announce/attachments/20260601/2f454fcc/attachment.sig>