Buffer Overflow Vulnerability in wolfSSL Product

CVE-2026-5503

What is CVE-2026-5503?

The vulnerability arises in the TLSX_EchChangeSNI function, where extensions are set unconditionally, even if the TLSX_Find function returns NULL. This oversight allows an attacker to control the publicName attached to the WOLFSSL_CTX due to improper SNI configuration. As a result, subsequent operations fail to clean up this data, leading to a buffer overflow when memcpy attempts to access memory beyond the allocated boundary. This flaw presents significant security implications, making it imperative for users to update to the latest version of wolfSSL to mitigate potential exploitation.

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