# CVE-2026-23220: ksmbd: fix infinite loop caused by next_smb2_rcv_hdr_off reset in error paths

CVE-2026-23220 is fixed in 36 products on 1 platform, first by DEBIAN-CVE-2026-23220, released February 18, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-23220
- Priority: Routine
- CVSS: 6.5 (Moderate)
- EPSS: 0.0014
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 18, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23220

## Description

In the Linux kernel, the following vulnerability has been resolved:  ksmbd: fix infinite loop caused by next_smb2_rcv_hdr_off reset in error paths  The problem occurs when a signed request fails smb2 signature verification check. In __process_request(), if check_sign_req() returns an error, set_smb2_rsp_status(work, STATUS_ACCESS_DENIED) is called. set_smb2_rsp_status() set work->next_smb2_rcv_hdr_off as zero. By resetting next_smb2_rcv_hdr_off to zero, the pointer to the next command in the chain is lost. Consequently, is_chained_smb2_message() continues to point to the same request header instead of advancing. If the header's NextCommand field is non-zero, the function returns true, causing __handle_ksmbd_work() to repeatedly process the same failed request in an infinite loop. This results in the kernel log being flooded with "bad smb2 signature" messages and high CPU usage.  This patch fixes the issue by changing the return value from SERVER_HANDLER_CONTINUE to SERVER_HANDLER_ABORT. This ensures that the processing loop terminates immediately rather than attempting to continue from an invalidated offset.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-uek ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-devel ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-devel ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-doc ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-doc ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-tools ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-tools ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | linux Debian 12.15 (bookworm) | 6.1.164-1 | [DEBIAN-CVE-2026-23220](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23220.md) | Feb 18, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.73-1 | [DEBIAN-CVE-2026-23220](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23220.md) | Feb 18, 2026 |
| Linux | linux Debian 14 | 6.18.12-1 | [DEBIAN-CVE-2026-23220](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23220.md) | Feb 18, 2026 |

---

Data as of 2026-11-08T19:12:23Z 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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