Bug 2468242 (CVE-2026-43383)

Summary: CVE-2026-43383 kernel: net/tcp-md5: Fix MAC comparison to be constant-time
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's TCP MD5 signature option. This vulnerability allows a remote attacker to perform timing attacks due to a non-constant-time comparison of Message Authentication Codes (MACs). By observing the time taken for MAC comparisons, an attacker could potentially infer sensitive information, which may aid in further exploitation.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-08 15:06:37 UTC
In the Linux kernel, the following vulnerability has been resolved:

net/tcp-md5: Fix MAC comparison to be constant-time

To prevent timing attacks, MACs need to be compared in constant
time.  Use the appropriate helper function for this.