CVE intelligence

CVE-2026-72034

Vulnerability intelligence

Published Aug 15, 2026Sources checked Oct 8, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-72034 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

CISA KEVNot listedBased on the latest collected catalog

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-72034?

In the Linux kernel, the following vulnerability has been resolved:

fhandle: reject detached mounts in capable_wrt_mount()

The recent fhandle RCU fix moved the mount namespace capability check into capable_wrt_mount(), so a non-NULL mnt_namespace survives the ns_capable() dereference. The helper still assumes the later READ_ONCE(mount->mnt_ns) must be non-NULL because may_decode_fh() checked is_mounted() first.

That assumption is not stable. A detached mount from open_tree(..., OPEN_TREE_CLONE) can be dissolved on fput while open_by_handle_at() is between those checks, and umount_tree() can clear mount->mnt_ns.

If the helper observes NULL, it dereferences mnt_ns->user_ns and panics.

Return false when the RCU read observes a detached mount. This keeps the relaxed permission path conservative: a mount no longer attached to a namespace cannot authorize open_by_handle_at() access.

Source: NVD