Out-of-bounds read in wolfSSL - CVE-2026-12340
Published: July 1, 2026
Vulnerability identifier: #VU136657
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-12340
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: wolfSSL
Affected software:
wolfSSL
wolfSSL
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in SM2/SM3 certificate signature verification when parsing a certificate with an SM3wSM2 signature and a short public key. A remote attacker can present a crafted certificate to cause a denial of service.
Only builds with SM2 support enabled are affected.
How to mitigate CVE-2026-12340
Install security update from vendor's website.