CVE-2026-6679

EUVD-2026-39557
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
wolfSSLCNA
8.8 HIGH
NETWORK
LOW
NONE
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
wolfsslwolfssl
5.4.0 ≤
𝑥
≤ 5.9.0
CNA
Common Weakness Enumeration
References
https://github.com/wolfSSL/wolfssl/pull/10116
https://www.wolfssl.com/docs/security-vulnerabilities/