Medium severity · published Feb 18, 2026
CVE-2026-23220
ksmbd: fix infinite loop caused by next_smb2_rcv_hdr_off reset in error paths
5.5
CVSS
0.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
5.15.145 before 5.16; 6.1.71 before 6.1.164; 6.6.1 before 6.6.125; 6.7 before 6.12.72; 6.13 before 6.18.11; 6.19 before 6.19.1; +3 more · source: NVD
LI
Linux · Linux
4b9b7ea1ffb1e34f01fa5726d0c184931b9ba565 before 544adb0a6658ea1bff4064723761dbf05f95b1e2; 943cebf9ea3415ddefcd670d24d8883e97ba3d60 before fb3b66bd72deb5543addaefa67963b34fb163a7b; be0f89d4419dc5413a1cf06db3671c9949be0d52 before 5accdc5b7f28a81bbc5880ac0b8886e60c86e8c8; be0f89d4419dc5413a1cf06db3671c9949be0d52 before f7b1c2f5642bbd60b1beef1f3298cbac81eb232c; be0f89d4419dc5413a1cf06db3671c9949be0d52 before 71b5e7c528315ca360a1825a4ad2f8ae48c5dc16; be0f89d4419dc5413a1cf06db3671c9949be0d52 before 9135e791ec2709bcf0cda0335535c74762489498; +4 more · source: vendor
RR
RUGGEDCOM RST2428P · Siemens
before V4.0 · source: CISA