Home / mailings

PDF

[USN-8779-2] Bubblewrap regression

Posted on 18 September 2026
Ubuntu Security

==========================================================================Ubuntu Security Notice USN-8779-2
September 17, 2026

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

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

Summary:

USN-8779-1 introduced a regression in Bubblewrap

Software Description:
- bubblewrap: Low-level unprivileged sandboxing tool used by Flatpak and similar projects

Details:

USN-8779-1 fixed vulnerabilities in Bubblewrap. Unfortunately, the fix for
CVE-2026-87766 introduced a regression in symlink resolution, preventing
certain Flatpak applications from launching. This update reverts that fix
until a complete fix is available.

We apologize for the inconvenience.

Original advisory details:

It was discovered that Bubblewrap incorrectly handled certain temporary
directories. A local attacker could possibly use this issue to cause a
denial of service or execute arbitrary code. This issue only affected
Ubuntu 18.04 LTS. (CVE-2019-12439)

It was discovered that Bubblewrap incorrectly handled certain symlinks
during sandbox setup. A local attacker could possibly use this issue to
create files outside of the sandbox. (CVE-2026-87766)

Update instructions:

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

Ubuntu 20.04 LTS
bubblewrap 0.4.0-1ubuntu4.1+esm3
Available with Ubuntu Pro

Ubuntu 18.04 LTS
bubblewrap 0.2.1-1ubuntu0.1+esm3
Available with Ubuntu Pro

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

References:
https://ubuntu.com/security/notices/USN-8779-2
https://ubuntu.com/security/notices/USN-8779-1
https://bugs.launchpad.net/ubuntu/+source/bubblewrap/+bug/2167621

Package Information:
https://launchpad.net/ubuntu/+source/bubblewrap/0.11.1-1ubuntu0.3
https://launchpad.net/ubuntu/+source/bubblewrap/0.9.0-1ubuntu0.3
https://launchpad.net/ubuntu/+source/bubblewrap/0.6.1-1ubuntu0.3

--===============6821599325285597113==Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature

 

TOP