Bug 2461754 (CVE-2026-31682)

Summary: CVE-2026-31682 kernel: bridge: br_nd_send: linearize skb before parsing ND options
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 bridge component. This vulnerability occurs because the system does not properly prepare network packet data before processing Neighbor Discovery (ND) options. An attacker could exploit this by sending specially crafted network packets, causing the system to read sensitive information from unintended memory locations or crash the system, leading to a denial of service.
 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 2026-04-25 09:01:23 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bridge: br_nd_send: linearize skb before parsing ND options

br_nd_send() parses neighbour discovery options from ns->opt[] and
assumes that these options are in the linear part of request.

Its callers only guarantee that the ICMPv6 header and target address
are available, so the option area can still be non-linear. Parsing
ns->opt[] in that case can access data past the linear buffer.

Linearize request before option parsing and derive ns from the linear
network header.
Comment 1 Alexander B 2026-04-27 10:01:05 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042545-CVE-2026-31682-fe50@gregkh/T