What’s Vulnerable › Vulnerabilities

CVE-2026-5447: Heap buffer overflow in CertFromX509() via AuthorityKeyIdentifier

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-09 · updated 2026-06-17
• Weakness: CWE-122

Description

Heap buffer overflow in CertFromX509 via AuthorityKeyIdentifier size confusion. A heap buffer overflow occurs when converting an X.509 certificate internally due to incorrect size handling of the AuthorityKeyIdentifier extension.

Affected products

• wolfSSL: before 5.9.1 — fixed in 5.9.1

How to fix

Upgrade to a fixed version: wolfSSL 5.9.1. Check the vendor advisory for mitigations.

References

• https://github.com/wolfSSL/wolfssl/pull/10112

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