Vulnerability · Published Apr 9, 2026 · Assigned by wolfSSL
CVE-2026-5264DTLS 1.3 ACK heap buffer overflow
High 8.3
In plain English
A high-severity heap buffer overflow in wolfSSL from wolfSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 4.0)8.3High
Exploit odds (30 days)0.5%top 60.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2026-5264 |
| Alpine:v3.24 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2026-5264 |
| Debian:12 | wolfssl | no fix listed | DEBIAN-CVE-2026-5264 |
| Debian:13 | wolfssl | no fix listed | DEBIAN-CVE-2026-5264 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5264 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5264 |
| Ubuntu:25.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-5264 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5264 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-5264 |
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N