CVE-2026-98123

A flaw was found in the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation. A remote attacker can cause a Denial of Service (DoS) by sending a specially crafted network packet during an active SCTP connection. A discrepancy in how parameter padding is processed causes the system to interpret misaligned data and enter an infinite loop, resulting in a CPU soft lockup that makes the system unresponsive. In certain conditions, missing length validation can also trigger an out-of-bounds memory read.

An inconsistency in SCTP ASCONF ACK parameter iteration can let a remote peer desynchronize verification from later parameter consumption. An odd length parameter can make sctp_get_asconf_response interpret attacker controlled bytes at a misaligned offset, and a decoded zero length can prevent the softirq loop from making progress. This can cause a CPU soft lockup and denial of service on a host with SCTP ADD IP enabled, an established association, and an outstanding ASCONF request. For the CVSS the PR:N value is used because a network peer can trigger the condition without local code execution or privileges on the target. The issue is remotely reachable over SCTP, although practical exposure depends on SCTP being permitted by network firewalls and on the required association state. A separate short ERR_CAUSE parameter can cause a bounded out of bounds read across the logical parameter boundary, but the read remains inside the received skb and does not provide a demonstrated kernel memory disclosure or write primitive. Impact is therefore denial of service without a supported privilege escalation path.

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.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.