CVE-2026-89636 in the critical feed json
smb: client: clear ce->tgthint in free_tgts()
published 2026-09-11 58 d ago modified 2026-10-19 21 d ago also EUVD-2026-76548
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 51%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
smb: client: clear ce->tgthint in free_tgts()
When free_tgts() frees all structures in ce->tlist, ce->tgthint is left pointing to one of the freed cache_dfs_tgt structures.
If ce->tgthint is not reset before it is used later, it results in a use-after-free.
Set ce->tgthint to NULL in free_tgts() after the elements are freed to reflect that no elements remain.
Patch / fix
- Linux Linux 6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4, 7.3
- linux Debian 12 6.1.190-1
- linux Debian 13 6.12.111-1
- linux Debian 14 7.2.6-1
- linux-6.12 Debian 12 6.12.111-1~deb12u1
debian advisories DEBIAN-CVE-2026-89636
- linux Ubuntu 26.04 LTS 7.0.0-42.42
- linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
- linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
- linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
- linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
- linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
- linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
- linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17
ubuntu advisories UBUNTU-CVE-2026-89636
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
- kernel-rt Linux Micro 6.2 6.12.0-160000.40.1
- kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.40.1
- kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.40.1
- kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.40.1
- kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.40.1.160000.2.29
- kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.40.1
- kernel-azure SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.40.1
- kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.40.1
suse advisories SUSE-SU-2026:5121-1SUSE-SU-2026:24422-1SUSE-SU-2026:24446-1SUSE-SU-2026:24437-1SUSE-SU-2026:24386-1SUSE-SU-2026:4706-1
- kernel-rt openSUSE Leap 16.0 6.12.0-160000.40.1
- dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-64kb openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-syms openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-azure openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-source openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-default openSUSE Leap 16.0 6.12.0-160000.40.1
opensuse advisories openSUSE-SU-2026:22167-1openSUSE-SU-2026:11880-1
- kernel Azure Linux 3.0 6.6.157.1-1
azure linux advisories AZL-100472
Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT
- git.kernel.org/stable/c/14f60e959b5ac813715ff72e127beb3584ddabf6 commit
- git.kernel.org/stable/c/3ff9462bb7a06d8d32a1dc02d39580b078ec9e55 commit
- git.kernel.org/stable/c/7507bd1885643d0461a6017767492450af1ce2a3 commit
- git.kernel.org/stable/c/9ab46a13798a61d9d020b01d4e57efdabe6624fa commit
- git.kernel.org/stable/c/5baab40404a9393bcc0b7b8f1950bf2c307e0984 commit
- git.kernel.org/stable/c/b1b741cf8e7ce1b91d937e23decd3d3358748700 commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-89636 updated cvss 4.7
kernel: smb: client: clear ce->tgthint in free_tgts()
-
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-9affected: workaround, no fix available
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 morenot 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
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 23 d ago
Exploit prediction
0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/14f60e959b5ac813715ff72e127beb3584ddabf6
- git.kernel.org /stable/c/3ff9462bb7a06d8d32a1dc02d39580b078ec9e55
- git.kernel.org /stable/c/7507bd1885643d0461a6017767492450af1ce2a3
- git.kernel.org /stable/c/9ab46a13798a61d9d020b01d4e57efdabe6624fa
- git.kernel.org /stable/c/5baab40404a9393bcc0b7b8f1950bf2c307e0984
- git.kernel.org /stable/c/b1b741cf8e7ce1b91d937e23decd3d3358748700
Sources
- CVE List CVE-2026-89636
- NVD CVE-2026-89636
Fencer Vulns 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.