What is CVE-2026-6679?

CVE-2026-6679 is a high-severity vulnerability in Wolfssl, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-06-25.

How severe is CVE-2026-6679?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in Wolfssl

CVE-2026-6679

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…

Vulnerability class: Integer Overflow

EPSS: 0.006 (44.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Wolfssl — versions 5.4.0

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound
CWE-197
CWE-787 — Out-of-bounds Write

References

facts@wolfssl.com (Patch, patch, Issue Tracking)
facts@wolfssl.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-6679?: CVE-2026-6679 is a high-severity vulnerability in Wolfssl, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-06-25.
How severe is CVE-2026-6679?: High severity. CVSS v3 base score is 7.5 out of 10.