CVE-2026-28386

A flaw was found in openssl. Applications using AES-CFB128 encryption or decryption on systems with AVX-512 and VAES support may experience a Denial of Service (DoS). This occurs when processing partial cipher blocks, specifically if the input buffer ends at a memory page boundary and the subsequent page is unmapped. This can lead to an out-of-bounds read of up to 15 bytes and a potential application crash.

This vulnerability has a Moderate impact on Red Hat products. It affects applications utilizing AES-CFB128 encryption or decryption on systems equipped with AVX-512 and VAES, potentially leading to a Denial of Service due to an out-of-bounds read when processing partial cipher blocks under specific memory conditions. The CFB mode is not employed in widely used protocols such as TLS/DTLS, which limits the applicability of this flaw.

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 do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.