# CVE-2026-99167: net/sched: fix use-after-free in __tcf_action_put()

CVE-2026-99167 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-99167, released November 3, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-99167
- Priority: High
- CVSS: 7.8 (Important)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 28, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-99167

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-99167](https://patchblox.com/security/data/fix/linux/debian-cve-2026-99167.md) | Nov 3, 2026 |
| Linux | linux Debian 14 | 7.2.13-1 | [DEBIAN-CVE-2026-99167](https://patchblox.com/security/data/fix/linux/debian-cve-2026-99167.md) | Nov 3, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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