CVE-2026-6679
HIGHDTLS 1.3 ACK serialization heap buffer overflow via integer truncation
Title source: cnaDescription
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.
References (2)
Core 2
Core References
Patch patch
https://github.com/wolfSSL/wolfssl/pull/10116
Scores
CVSS v3
7.5
EPSS
0.0058
EPSS Percentile
44.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-190
CWE-197
CWE-787
Status
published
Products (2)
wolfSSL/wolfSSL
5.4.0 - 5.9.0
wolfssl/wolfssl
5.4.0 - 5.9.1
Published
Jun 25, 2026
Tracked Since
Jun 26, 2026