Critical severity · published Apr 9, 2026
CVE-2026-5264
DTLS 1.3 ACK heap buffer overflow
9.8
CVSS
0.4%
EPSS
No
On KEV
Description
Heap buffer overflow in DTLS 1.3 ACK message processing. A remote attacker can send a crafted DTLS 1.3 ACK message that triggers a heap buffer overflow.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 39% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WO
wolfSSL · wolfSSL
before 5.9.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5264
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-5264
Issue Tracking
https://github.com/wolfssl/wolfssl/pull/10076
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