Medium 5.5Published Feb 18, 2026

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

Updated under an hour ago (Oct 27, 2026, 5:50 PM ET)

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Exploited in the last 30 days

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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Jun 2, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 4b9b7ea1ffb1e34f01fa5726d0c184931b9ba565 before 544adb0a6658ea1bff4064723761dbf05f95b1e2; from 943cebf9ea3415ddefcd670d24d8883e97ba3d60 before fb3b66bd72deb5543addaefa67963b34fb163a7b; from be0f89d4419dc5413a1cf06db3671c9949be0d52 before 5accdc5b7f28a81bbc5880ac0b8886e60c86e8c8; from be0f89d4419dc5413a1cf06db3671c9949be0d52 before f7b1c2f5642bbd60b1beef1f3298cbac81eb232c; from be0f89d4419dc5413a1cf06db3671c9949be0d52 before 71b5e7c528315ca360a1825a4ad2f8ae48c5dc16; from be0f89d4419dc5413a1cf06db3671c9949be0d52 before 9135e791ec2709bcf0cda0335535c74762489498; from be0f89d4419dc5413a1cf06db3671c9949be0d52 before 010eb01ce23b34b50531448b0da391c7f05a72af; from 5.15.145 before 5.15.203; and 1 more ranges	CNA record
Siemens RUGGEDCOM RST2428P siemens:ruggedcom_rst2428p (from the name)	before V4.0	CISA ADP
linux linux_kernel linux:linux_kernel	from 5.15.145 before 5.16; from 6.1.71 before 6.1.164; from 6.6.1 before 6.6.125; from 6.7 before 6.12.72; from 6.13 before 6.18.11; from 6.19 before 6.19.1; 6.6; 6.6; and 1 more ranges	NVD

References

References

https://git.kernel.org/stable/c/544adb0a6658ea1bff4064723761dbf05f95b1e2
https://git.kernel.org/stable/c/fb3b66bd72deb5543addaefa67963b34fb163a7b	patch
https://git.kernel.org/stable/c/5accdc5b7f28a81bbc5880ac0b8886e60c86e8c8	patch
https://git.kernel.org/stable/c/f7b1c2f5642bbd60b1beef1f3298cbac81eb232c	patch
https://git.kernel.org/stable/c/71b5e7c528315ca360a1825a4ad2f8ae48c5dc16	patch
https://git.kernel.org/stable/c/9135e791ec2709bcf0cda0335535c74762489498	patch
https://git.kernel.org/stable/c/010eb01ce23b34b50531448b0da391c7f05a72af	patch
https://cert-portal.siemens.com/productcert/html/ssa-253495.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.