CVE-2026-15422 is a critical heap-based buffer overflow vulnerability in the illumos-gate SCTP inbound path. The vulnerability arises because the SCTP association lookup for INIT ACK chunks does not adequately validate the address parameters contained in the chunk. This lookup occurs during packet classification before SCTP integrity checks or IPsec policies are applied, allowing a remote unauthenticated attacker to send a crafted SCTP INIT ACK packet with malformed address parameters. This can cause an out-of-bounds access leading to kernel heap corruption and potentially remote code execution. The flaw has existed since 2010 (illumos-gate commit a5407c02) and affects all illumos distributions prior to illumos-gate commit 53a3efde. No patch or official remediation level has been published as of now.

A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted SCTP INIT ACK packet, causing out-of-bounds memory access and kernel heap corruption. This may lead to remote code execution on the affected system. The vulnerability impacts system integrity and availability, posing a critical risk to affected illumos systems.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary mitigation has been published at this time. Until a patch is available, consider restricting SCTP traffic from untrusted sources or applying network-level controls to limit exposure.