X.509 Trust-Chain Bypass in wolfSSL TLS/DTLS Library
CVE-2026-11310

8.7HIGH

Key Information:

Vendor

Wolfssl

Status
Wolfssl
Vendor
CVE Published:
25 June 2026

What is CVE-2026-11310?

The wolfSSL library contains a vulnerability in its X.509 trust-chain validation feature, specifically within the function designed for OpenSSL compatibility. This issue arises when builds are configured with --enable-opensslextra, allowing applications to validate certificates using caller-supplied untrusted intermediate certificates. An attacker can exploit this vulnerability by presenting a malicious certificate chain that does not reach a configured trust anchor, thus allowing the acceptance of an attacker-controlled certificate. Although native wolfSSL's TLS/DTLS functionality remains unaffected, applications utilizing manual or deferred peer verification via X509_verify_cert() with this configuration face significant risks. This compromises various certificate validation contexts, including S/MIME/CMS and firmware signing, making proper configuration and awareness vital for maintaining security.

Affected Version(s)

wolfSSL 5.8.4 <= 5.9.1

References

https://github.com/wolfSSL/wolfssl/pull/10674
patch
https://www.wolfssl.com/docs/security-vulnerabilities/

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Corban Villa, Sohee Kim and Austin Chu (UC Berkeley, Sky Lab)
.