Home / mailings [SECURITY] [DSA 6462-1] zfs-linux security update
Posted on 24 August 2026
Debian Security Advisory- -------------------------------------------------------------------------
Debian Security Advisory DSA-6462-1 security@debian.org
https://www.debian.org/security/ Aron Xu
August 24, 2026 https://www.debian.org/security/faq
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Package : zfs-linux
Erica Windisch reported several vulnerabilities in the Linux
implementation of OpenZFS, a filesystem and volume manager.
The administrative operations exposed by the /dev/zfs ioctl interface
accepted the CAP_SYS_ADMIN capability in the calling process's own user
namespace as authority over pools on the host, instead of requiring it
in the initial user namespace. In addition, opening a vdev did not
check that the caller was permitted to access the underlying device
node or backing file. Since /dev/zfs is world-accessible and
unprivileged user namespaces are enabled by default, a local user can
take advantage of these flaws to administer pools on the host, to
attach and write to devices they have no permission to access, and
thereby to escalate privileges or cause a denial of service. The same
flaws allow a process in a container to which /dev/zfs is exposed to
act on the host storage stack.
This update is based on the upstream 2.3.9 release, which also contains
a number of fixes for data corruption, kernel panics and deadlocks.
For the stable distribution (trixie), this problem has been fixed in
version 2.3.9-0+deb13u1.
We recommend that you upgrade your zfs-linux packages.
For the detailed security status of zfs-linux please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/zfs-linux
Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/
Mailing list: debian-security-announce@lists.debian.org
