CVE-2026-5778
Medium
Description
Integer underflow in wolfSSL packet sniffer <= 5.9.0 allows an attacker to cause a program crash in the AEAD decryption path by injecting a TLS record shorter than the explicit IV plus authentication tag into traffic inspected by ssl_DecodePacket. The underflow wraps a 16-bit length to a large value that is passed to AEAD decryption routines, causing a large out-of-bounds read and crash. An unauthenticated attacker can trigger this remotely via malformed TLS Application Data records.
SeverityMedium
CVSS6.5
Exploit probability—
ProductWolfssl
PublishedApr 9, 2026
First seenApr 9, 2026
Weakness typeCWE-191CWE-191
How to fix
Update
- wolfssl wolfssl5.9.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| wolfssl wolfssl | v < 5.9.1 | 5.9.1 |
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