Packages
- 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)
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
In general, a standard system update will make all the necessary changes.
Learn more about how to get the fixes.The problem can be corrected by updating your system to the following package versions:
| Ubuntu Release | Package Version | ||
|---|---|---|---|
| 20.04 LTS focal | bubblewrap – 0.4.0-1ubuntu4.1+esm3 | ||
| 18.04 LTS bionic | bubblewrap – 0.2.1-1ubuntu0.1+esm3 | ||
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