CVE-2026-98994 json
statmount: read the parent of an unmounted mount under mount_lock
published 19d ago modified 19d ago also EUVD-2026-108788
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 4%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
statmount: read the parent of an unmounted mount under mount_lock
statmount_mnt_basic() reads the ids of the parent through m->mnt_parent with namespace_sem held for reading. That's fine for a mount that is in a namespace. Everything above it is pinned by that namespace.
STATMOUNT_BY_FD also accepts a file descriptor on a mount that has been unmounted on purpose and that only the file descriptor keeps alive. If that mount stayed attached to its parent when it was unmounted the parent is unmounted as well and nothing pins it for the child.
The final mntput() unmounts the children under mount_lock alone and frees the parent afterwards. Concurrently, statmount_mnt_basic() reads m->mnt_parent twice while that can happen and can easily dereference a mount that's already gone.
Read the parent of an unmounted mount under mount_lock. The parent can't be put while it is held and both ids come from the same mount. A mounted mount's parent is pinned by the namespace and a mount can't leave its namespace while namespace_sem is held, so the common case takes no global lock.
Patch / fix
- Linux Linux 7.3
- linux Debian 14 7.2.11-1
debian advisories DEBIAN-CVE-2026-98994
- linux Ubuntu 26.10 7.3.0-10.10
- linux-aws Ubuntu 26.10 7.3.0-1004.4
- linux-gcp Ubuntu 26.10 7.3.0-1004.4
- linux-raspi Ubuntu 26.10 7.3.0-1004.4
- linux-riscv Ubuntu 26.10 7.3.0-10.10.1
- linux-oracle Ubuntu 26.10 7.3.0-1004.4
- linux-realtime Ubuntu 26.10 7.3.0-10.10.1
ubuntu advisories UBUNTU-CVE-2026-98994
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
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Check with FencerVendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-98994 updated cvss 5.5
kernel: statmount: read the parent of an unmounted mount under mount_lock
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Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 moreaffected: no fix planned “Out of support scope”
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Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9not affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-11).
Affected products
- Linux Linux
Classification
- Technology feeds
References
Sources
- CVE List CVE-2026-98994
- NVD CVE-2026-98994
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.