# CVE-2026-98441: net/sched: act_ct: avoid modifying shared unconfirmed ct entry

CVE-2026-98441 is fixed in 37 products on 1 platform, first by DEBIAN-CVE-2026-98441, released October 19, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-98441
- Priority: High
- CVSS: 8.1 (Important)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 18, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98441

## Description

In the Linux kernel, the following vulnerability has been resolved:  net/sched: act_ct: avoid modifying shared unconfirmed ct entry  In a case where skb with an unconfirmed ct entry gets cloned, we may end up processing both again but with different sets of extensions.  The series of events:   1. The first clone wants to commit and runs the helpers wiring up     the extension pointer into the expectation list.  2. Then it looses the confirmation keeping the entry unconfirmed.  3. Second clone now wants to commit labels or run NAT and adds the     new extension for that breaking the pointer in the expectation     list causing UAF on the destruction path later.  While this is possible to trigger, there should be no practical network pipeline where we need to process both clones without modifications in the same zone.  So, let's just reset the entry in case for some reason we got an skb with a shared one.  This doesn't affect any known use cases, but avoids any potential problems with sharing and modification of the unconfirmed ct entry.  Unlike openvswitch module, act_ct allows for NAT without commit. Changing that would be a uAPI break.  So, act_ct needs to reset on NAT regardless of the commit flag to avoid reallocation of the extension space.  This, however, doesn't really change the picture for sensible networking cases as there should be no need to run the same packet twice (before and after the clone) through conntrack without packet header or zone changes and without commit.  The fixes tag points to the introduction of helpers, since that's the main UAF trigger for the sharing.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-uek ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-doc ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-doc ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-tools ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-tools ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.113-1 | [DEBIAN-CVE-2026-98441](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98441.md) | Oct 19, 2026 |
| Linux | linux Debian 14 | 7.2.9-1 | [DEBIAN-CVE-2026-98441](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98441.md) | Oct 19, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.113-1~deb12u1 | [DEBIAN-CVE-2026-98441](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98441.md) | Oct 19, 2026 |

---

Data as of 2026-11-08T06:59:42Z 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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