[USN-8702-1] util-linux vulnerabilities

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Ubuntu Security Notice USN-8702-1
August 31, 2026

util-linux vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 26.04 LTS
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS

Summary:

Several security issues were fixed in util-linux.

Software Description:
- util-linux: miscellaneous system utilities

Details:

It was discovered that libblkid in util-linux had a heap use-after-free
vulnerability during nested partition probing. An attacker who could
present a crafted block device image could possibly use this issue to
obtain sensitive information or cause a denial of service. (CVE-2026-13595)

It was discovered that the mount utility in util-linux had a time-of-check-
time-of-use vulnerability when setting up loop devices. A local attacker
could possibly use this issue to obtain unauthorized read access to root-
protected files and block devices. (CVE-2026-27456)

It was discovered that the login utility in util-linux improperly
canonicalized hostnames when invoked with the -h option. A remote attacker
could possibly use this issue to bypass host-based access control rules.
This issue only affected Ubuntu 26.04 LTS. (CVE-2026-3184)

It was discovered that libmount in util-linux had a time-of-check-time-of-
use vulnerability in its ownership hook. A local attacker could possibly
use this issue to gain elevated privileges. This issue only affected Ubuntu
24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-53612)

It was discovered that libmount in util-linux had a time-of-check-time-of-
use vulnerability that allowed target path redirection during mount
operations. A local attacker could possibly use this issue to gain elevated
privileges. (CVE-2026-53613)

It was discovered that libmount in util-linux improperly handled the
LIBMOUNT_FORCE_MOUNT2 environment variable in the SUID mount utility. A
local attacker could possibly use this issue to bypass nosuid and noexec
mount options and gain elevated privileges. This issue only affected Ubuntu
24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-53614)

It was discovered that libblkid in util-linux had an integer overflow
vulnerability when parsing DOS partition tables. An attacker who could
present a crafted block device image could possibly use this issue to cause
a denial of service. (CVE-2026-53615)

Update instructions:

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

Ubuntu 26.04 LTS
  util-linux                      2.41.3-3ubuntu2.2

Ubuntu 24.04 LTS
  util-linux                      2.39.3-9ubuntu6.6

Ubuntu 22.04 LTS
  util-linux                      2.37.2-4ubuntu3.6

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

References:
  https://ubuntu.com/security/notices/USN-8702-1
  CVE-2026-13595, CVE-2026-27456, CVE-2026-3184, CVE-2026-53612,
  CVE-2026-53613, CVE-2026-53614, CVE-2026-53615

Package Information:
  https://launchpad.net/ubuntu/+source/util-linux/2.41.3-3ubuntu2.2
  https://launchpad.net/ubuntu/+source/util-linux/2.39.3-9ubuntu6.6
  https://launchpad.net/ubuntu/+source/util-linux/2.37.2-4ubuntu3.6
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