CVE-2026-15422: illumos illumos-gate Heap-based Buffer Overflow

Vulnerability summary

CVE-2026-15422 is a critical (CVSS 9.1) Heap-based Buffer Overflow vulnerability in illumos illumos-gate. EPSS estimates a 0.88% chance of exploitation in the next 30 days, higher than 58.5% of scored vulnerabilities.

Timeline

1. 16-07-2026
   PublishedVulnerability first disclosed.
2. 17-07-2026
   Last modifiedVulnerability information updated.

Description

The illumos SCTP inbound path performs association lookup for INIT ACK chunks without adequately validating the address parameters carried in the chunk. Since this lookup runs during packet classification (i.e. before SCTP integrity checks or IPsec policy are applied) a remote, unauthenticated attacker can send a crafted SCTP INIT ACK packet with malformed address parameters to cause an out-of-bounds access and kernel heap corruption, which may lead to remote code execution. The flaw has existed since 2010 (illumos-gate commit a5407c02), and affects any illumos distribution prior to illumos-gate commit 53a3efde.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.