What’s Vulnerable › Vulnerabilities

CVE-2026-5264: DTLS 1.3 ACK heap buffer overflow

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% 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 DTLS 1.3 ACK message processing. A remote attacker can send a crafted DTLS 1.3 ACK message that triggers a heap buffer overflow.

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/10076

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