Executive brief
A security vulnerability exists in the wolfSSL library, which is used to secure communications for embedded devices and cloud applications. An attacker could send a specially crafted encrypted message (such as an S/MIME email) that causes the software to read memory outside of its intended boundaries. While this specific issue primarily impacts the stability of the application, it could lead to service disruptions or crashes.
Technical details
A heap buffer overread vulnerability (CWE-125) exists in wolfSSL within the 'wc_PKCS7_DecodeEnvelopedData' function. The issue is caused by a missing bounds check before caching encrypted content during the decoding of PKCS7 EnvelopedData. An attacker can exploit this by providing malicious data via S/MIME or Cryptographic Message Syntax (CMS) structures. While the impact is primarily limited to a denial-of-service (crash) due to the out-of-bounds read, it represents a failure in input validation. The vulnerability is addressed in wolfSSL version 5.9.2.
Affected products
- wolfSSL wolfSSL 5.8.0 to 5.9.1
Timeline
- 2026-04-23: patched: Fix merged into master branch via PR 10128
- 2026-06-25: disclosed: CVE published to NVD