PT-2026-20446 · Linux · Linux Kernel

Published

2026-01-01

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Updated

2026-05-26

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CVE-2026-23220

CVSS v3.1

5.5

Medium

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description An issue exists in the Linux kernel’s ksmbd module where an infinite loop can occur due to an incorrect reset of the next smb2 rcv hdr off pointer in error paths during SMB2 signature verification. Specifically, when a signed request fails signature verification, the check sign req() function returns an error, and set smb2 rsp status() resets next smb2 rcv hdr off to zero. This causes the is chained smb2 message() function to repeatedly process the same failed request, leading to an infinite loop, high CPU usage, and flooding of the kernel log with "bad smb2 signature" messages. The issue is addressed by changing the return value from SERVER HANDLER CONTINUE to SERVER HANDLER ABORT, ensuring the processing loop terminates correctly.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Infinite Loop

Weakness Enumeration

Related Identifiers

CVE-2026-23220
ECHO-A8CD-8315-0161
OESA-2026-1566
OESA-2026-1567
OESA-2026-1570
OPENSUSE-SU-2026:10387-1

Affected Products

Linux Kernel