CVE-2026-5500: Improper Validation of AES-GCM Authentication Tag Length in PKCS#7 Envelope Allows Authentication Bypass
wolfSSL's wcPKCS7DecodeAuthEnvelopedData() does not properly sanitize the AES-GCM authentication tag length received and has no lower bounds check. A man-in-the-middle can therefore truncate the mac field from 16 bytes to 1 byte, reducing the tag check from 2⁻¹²⁸ to 2⁻⁸.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-5500?
CVE-2026-5500 has not been assigned a severity rating yet, but it poses a significant risk due to potential authentication bypass.
How do I fix CVE-2026-5500?
To fix CVE-2026-5500, ensure you update to the latest version of wolfSSL where the vulnerability has been addressed.
What are the potential impacts of CVE-2026-5500?
The potential impacts of CVE-2026-5500 include unauthorized access to encrypted data due to an authentication bypass.
Who is affected by CVE-2026-5500?
CVE-2026-5500 affects users of wolfSSL that utilize AES-GCM for authentication in PKCS#7 encrypted data.
Can CVE-2026-5500 be exploited remotely?
Yes, CVE-2026-5500 can be exploited remotely through man-in-the-middle attacks that take advantage of the improper validation.