CVE-2026-5500
Improper Validation of AES-GCM Authentication Tag Length in PKCS#7 Envelope Allows Authentication Bypass
- State
- Published
- Severity
- 8.7 High
- Published
- Apr 10, 2026
- Updated
- Apr 10, 2026
- Reserved
- Apr 3, 2026
Description
wolfSSL's wc_PKCS7_DecodeAuthEnvelopedData() 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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N | wolfSSL |
Weaknesses
- CWE-20 Improper input validation
Affected Products
| Product | Versions |
|---|---|
wolfSSLwolfSSL |
|
References
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