CVE-2025-15467
openssl: OpenSSL: Remote code execution or Denial of Service via oversized Initialization Vector in CMS parsing
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · January 27, 2026
Updated · October 15, 2026
Description
A flaw was found in OpenSSL. A remote attacker can exploit a stack buffer overflow vulnerability by supplying a crafted Cryptographic Message Syntax (CMS) message with an oversized Initialization Vector (IV) when parsing AuthEnvelopedData structures that use Authenticated Encryption with Associated Data (AEAD) ciphers such as AES-GCM. This can lead to a crash, causing a Denial of Service (DoS), or potentially allow for remote code execution.
Statement
This vulnerability is rated Important for Red Hat products. On Red Hat Enterprise Linux, OpenSSL is built with stack protections enabled which mitigate the risk of code execution though a denial-of-service condition remains possible. This vulnerability only affects applications and services that parse untrusted CMS or PKCS#7 content using AEAD ciphers, such as Kerberos using the PKINIT plugin. OpenSSL versions 1.1.1 and 1.0.2 are not affected by this issue.
CVSS score applicability
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
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.
CVSS / CWE
CVSS 3.1 · 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')