Researchers at JFrog have discovered a potentially critical remote code execution (RCE) vulnerability in OpenSSL, identified as CVE-2025-15467. The flaw stems from a stack buffer overflow triggered by a crafted CMS AuthEnvelopedData message with maliciously constructed parameters. Affected versions include OpenSSL 3.0, 3.3, 3.4, 3.5, and 3.6, posing a serious threat to systems using these.

This vulnerability allows attackers to exploit the stack overflow by sending a specially crafted message, potentially leading to unauthorized code execution. The issue arises when OpenSSL copies the initialization vector (IV) from the CMS structure into a fixed-size buffer without proper length validation. This could affect applications that use S/MIME for secure email or handle PKCS#7 content.

The impact is amplified because the overflow occurs before authentication. This means an attacker doesn't need valid encryption keys to trigger it. Users should immediately upgrade to the patched versions: 3.0.19, 3.3.6, 3.4.4, 3.5.5, and 3.6.1. Keep an eye out for further updates and potential exploitation details.

OpenSSL is a widely-used cryptography library that is embedded in countless applications, making this vulnerability particularly concerning. The ability to achieve RCE through a crafted message highlights the importance of keeping software up-to-date and the constant need for security vigilance in the developer community.