CVE-2026-6679

highCVSS 7.5covered by 1 sourcefirst seen 2026-06-25

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.

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Exploitation outlook

Low exploitation risk0.39% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 31% of all EPSS-scored CVEs.

Advisory coverage (1)

highCVE-2026-6679: A heap buffer overflow could occur in the DTLS 1.3 ACK serialization path before the connecting…nvd · 2026-06-25

External references

NVD record for CVE-2026-6679

CVE.org record

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