Vulnerability · CVE-2026-99167

In the Linux kernel, the following vulnerability has been resolved: net/sched: fix use-after-free in __tcf_action_put() __tcf_action_put() decrements the reference count before dec

Published Oct 28, 2026 · catalog updated Nov 1, 2026 · In the Linux kernel,

Last checked Nov 4, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-99167. EPSS is 0.13%. Act only if a listed version of In the Linux kernel, is installed.

Gaps on this record

The stored product name is a package slug. The name on this page is taken from the title (In the Linux kernel,).
No vendor fix or required action is stored. Compare the linked advisory before you change production.

Severity: High7.8
Known exploitation: Not in CISA/VulnCheck KEV
EPSS: 0.13%
Remediation: Advisory link
Affected products: Debian:12 linux · Debian:13 linux · Debian:14 linux · Ubuntu:16.04:LTS linux-hwe-edge · Ubuntu:18.04:LTS linux-aws-5.0 · Ubuntu:18.04:LTS linux-aws-5.3

In the Linux kernel, the following vulnerability has been resolved: net/sched: fix use-after-free in __tcf_action_put() __tcf_action_put() decrements the reference count before decrementing the binding count. Another thread can free the action between these operations, causing the binding-count update to access freed memory. KASAN reports it as: BUG: KASAN: slab-use-after-free in __tcf_action_put+0x327/0x340 Write of size 4 at addr ff11000000d46420 by task tc-put-pause/64 Hold the action IDR mutex across both counter updates and IDR removal, keeping cleanup outside the lock.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

Debian:12 linux6.1.106-1, 6.1.106-2, 6.1.106-3
Debian:13 linux6.12.100-1, 6.12.101-1, 6.12.105-1
Debian:14 linux6.12.100-1, 6.12.101-1, 6.12.105-1
Ubuntu:16.04:LTS linux-hwe-edge4.8.0-28.30~16.04.1, 4.8.0-30.32~16.04.1, 4.8.0-32.34~16.04.1
Ubuntu:18.04:LTS linux-aws-5.05.0.0-1021.24~18.04.1, 5.0.0-1022.25~18.04.1, 5.0.0-1023.26~18.04.1
Ubuntu:18.04:LTS linux-aws-5.35.3.0-1016.17~18.04.1, 5.3.0-1017.18~18.04.1, 5.3.0-1019.21~18.04.1
Ubuntu:18.04:LTS linux-azure4.15.0-1002.2, 4.15.0-1003.3, 4.15.0-1004.4
Ubuntu:18.04:LTS linux-azure-5.35.3.0-1007.8~18.04.1, 5.3.0-1008.9~18.04.1, 5.3.0-1009.10~18.04.1
Ubuntu:18.04:LTS linux-azure-edge4.18.0-1006.6~18.04.1, 4.18.0-1007.7~18.04.1, 4.18.0-1008.8~18.04.1
Ubuntu:18.04:LTS linux-gcp4.15.0-1001.1, 4.15.0-1003.3, 4.15.0-1005.5
Ubuntu:18.04:LTS linux-gcp-5.35.3.0-1008.9~18.04.1, 5.3.0-1009.10~18.04.1, 5.3.0-1010.11~18.04.1
Ubuntu:18.04:LTS linux-gke-4.154.15.0-1030.32, 4.15.0-1032.34, 4.15.0-1033.35
Ubuntu:Pro:18.04:LTS linux-aws-5.45.4.0-1018.18~18.04.1, 5.4.0-1020.20~18.04.2, 5.4.0-1022.22~18.04.1
Ubuntu:Pro:18.04:LTS linux-azure-5.45.4.0-1020.20~18.04.1, 5.4.0-1022.22~18.04.1, 5.4.0-1023.23~18.04.1
Ubuntu:Pro:18.04:LTS linux-gcp-5.45.4.0-1019.19~18.04.2, 5.4.0-1021.21~18.04.1, 5.4.0-1022.22~18.04.1

How to fix CVE-2026-99167

No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
Seen in 6.1.106-1 · 17 other packages on the advisory
Advisory
Open the bsi record and follow its fix.
Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-99167. EPSS is 0.13%. Act only if a listed version of In the Linux kernel, is installed.

Which versions are affected?

Compare what you have installed with 6.1.106-1, 6.1.106-2, 6.1.106-3, 6.12.100-1, 6.12.101-1, 6.12.105-1, 4.8.0-28.30~16.04.1, 4.8.0-30.32~16.04.1, 4.8.0-32.34~16.04.1, 5.0.0-1021.24~18.04.1, 5.0.0-1022.25~18.04.1, 5.0.0-1023.26~18.04.1, 5.3.0-1016.17~18.04.1, 5.3.0-1017.18~18.04.1, 5.3.0-1019.21~18.04.1, 4.15.0-1002.2, 4.15.0-1003.3, 4.15.0-1004.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.13%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security Ubuntu security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

Oct 28, 2026 · Tenable CVE Database
Detected
In the Linux kernel, the following vulnerability has been resolved: net/sched: fix use-after-free in __tcf_action_put() __tcf_action_put() decrements the reference count before decrementing the binding count. Another thread can free the action between these operations, causing the binding-count update to access freed memory. KASAN reports it as: BUG: KASAN: slab-use-after-free in __tcf_action_put+
Oct 30, 2026 · OpenSSF OSV / OSV Scanner
Updated
In the Linux kernel, the following vulnerability has been resolved: net/sched: fix use-after-free in __tcf_action_put() __tcf_action_put() decrements the reference count before decrementing the binding count. Another thread can free the action between these operations, causing the binding-count update to access freed memory. KASAN reports it as: BUG: KASAN: slab-use-after-free in __tcf_action_put+
Nov 1, 2026 · Trivy Vulnerability DB
Updated
In the Linux kernel, the following vulnerability has been resolved: net/sched: fix use-after-free in __tcf_action_put() __tcf_action_put() decrements the reference count before decrementing the binding count. Another thread can free the action between these operations, causing the binding-count update to access freed memory. KASAN reports it as: BUG: KASAN: slab-use-after-free in __tcf_action_put+

Sources

BSI CERT-BundGovernment advisoryCVE-2026-99167
Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff
wid.cert-bund.de
CVE.orgVulnerability recordCVE-2026-99167
Official CVE identifier
cve.org
FIRST EPSSExploitation probabilityCVE-2026-99167
30-day exploitation probability 0.13%
first.org
OpenSSF OSV / OSV ScannerPackage advisoryUBUNTU-CVE-2026-99167
osv.dev
Tenable CVE DatabaseVulnerability recordCVE-2026-99167
In the Linux kernel, the following vulnerability has been resolved: net/sched: fix use-after-free in __tcf_action_put() __tcf_action_put() decrements the reference count before decrementing the binding count. Another thread can free the action between these operations, causing the binding-count update to access freed memory. KASAN reports it as: BUG: KASAN: slab-use-after-free in __tcf_action_put+
tenable.com
Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-99167
In the Linux kernel, the following vulnerability has been resolved: net/sched: fix use-after-free in __tcf_action_put() __tcf_action_put() decrements the reference count before decrementing the binding count. Another thread can free the action between these operations, causing th
osv.dev

References

Freshness

Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

FIRST EPSSNov 4, 2026
Trivy Vulnerability DBNov 1, 2026
Tenable CVE DatabaseNov 1, 2026
OpenSSF OSV / OSV ScannerOct 31, 2026
BSI CERT-BundOct 30, 2026
CVE.orgOct 28, 2026

Priority score

24/100

Evidence confidence: High

A vendor or government advisory agrees with at least one other source.

Confirmed exploitation0/30
EPSS probability1/20
CVSS severity12/15
Public exploit0/10
Internet exposure6/10
Product prevalence5/5
Detection0/5
Threat research0/5

Decision signals

Four separate signals — do not infer one from another.

High

CVSS severity
7.8 v3.1
Technical impact. Separate from exploitation likelihood.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS probability
0.13% · p2.63%
Estimated probability of exploitation within 30 days (FIRST).
Known exploitation
No verified KEV listing
Evidence from CISA KEV or VulnCheck KEV only — not from EPSS alone.
Patch availability
Advisory link
A patch or advisory reference is linked. Open the original publisher for availability by product version.

Stacks

Debian Debian 12 Debian 13 Debian 14 Linux Ubuntu Ubuntu 16.04 Ubuntu 18.04

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