CVE-2026-98532

A flaw was found in the Linux kernel. A remote attacker could cause a Denial of Service (DoS) or memory corruption by sending specially crafted IPv6 network packets. The IPv6 extension header parsing mechanism fails to verify that the declared length of a header fits within the received packet data, resulting in an offset that points past the end of the buffer. Subsequent networking operations that process this invalid offset perform out-of-bounds memory reads and writes, triggering a kernel crash.

This vulnerability is rated as having an Important impact because an unauthenticated remote attacker can cause a denial of service by transmitting malformed IPv6 packets across the network without requiring privileges or user interaction. In standard Red Hat Enterprise Linux and OpenShift deployments, the IPv6 networking stack is enabled by default, leaving systems exposed if they receive untrusted external traffic or utilize packet inspection frameworks like Open vSwitch. Although out-of-bounds memory operations occur during header parsing, the primary risk in production environments is an immediate kernel panic resulting in system downtime.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

--- CME Mitigation Guidance (2026-10-20) --- Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.

The highest-value action is to enforce packet length bounds checks against skb->len within ipv6_find_hdr() extension header processing: upgrade to the fixed Kernel/Kernel Rt/Kernel Ivos Qualcomm/Openshift/Ose Rhel Coreos/Kpatch builds, which reject an extension header and return -EBADMSG if its declared length exceeds the remaining packet bytes (skb->len - start), closing all 2 injection vectors (crafted IPv6 network packet with oversized extension header length, Netlink packet command execution triggering Open vSwitch transport header parsing). Until patched, this is a concern on Linux systems running IPv6 networking stack, so restrict untrusted IPv6 traffic or disable unneeded IPv6 packet processing interfaces. As a compensating measure, enable kernel memory allocation error detection (KASAN/HWASan) to detect out-of-bounds slab memory accesses during IPv6 extension header parsing. These controls limit blast radius and contain exploitation, but they do not fix the underlying out-of-bounds memory read and write defect — apply the upstream patch to fully remediate.

Highest-impact CME: CME-1005 Runtime Memory Error Detection (KASAN/HWASan) (medium)