CVE-2026-6679: DTLS 1.3 ACK serialization heap buffer overflow via integer truncation
A heap buffer overflow could occur in the DTLS 1.3 ACK serialization path before the connecting peer is authenticated. The buffer overflow was due to an integer truncation when computing the length of the ACK record-number list, causing an undersized buffer to be allocated and then overrun. This affects builds using DTLS 1.3 and wolfSSL version 5.9.0 and earlier. A fix was added to the 5.9.1 release.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
wolfSSLto a version that resolves this vulnerability.Fixed in 5.9.1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-6679?
CVE-2026-6679 has a high severity rating of 8.8 on the CVSS scale.
How do I fix CVE-2026-6679?
To fix CVE-2026-6679, update to a patched version of wolfSSL that addresses the heap buffer overflow.
What type of vulnerability is CVE-2026-6679?
CVE-2026-6679 is a heap buffer overflow vulnerability caused by integer truncation in the DTLS 1.3 ACK serialization path.
Which software is affected by CVE-2026-6679?
CVE-2026-6679 affects the wolfSSL library.
What impacts could CVE-2026-6679 have on my system?
Exploitation of CVE-2026-6679 could allow an attacker to execute arbitrary code on the system before peer authentication.