CVE-2026-12340

Out-of-bounds heap read during SM2/SM3 certificate signature verification. When parsing a certificate with an SM3wSM2 signature, the Subject Key Identifier computation reads the trailing 65 bytes of the public key without checking that the key is at least that long. A public key shorter than 65 bytes results in an out-of-bounds heap read, leading to a potential crash (denial of service); there is no out-of-bounds write. Note this only affects builds with SM2 support (--enable-sm2 or --enable-all).

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/wolfSSL/wolfssl/pull/10641	Issue Tracking Patch
https://www.wolfssl.com/docs/security-vulnerabilities/	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*

History

26 Jun 2026, 18:54

Type	Values Removed	Values Added
References	~~() https://github.com/wolfSSL/wolfssl/pull/10641 -~~	() https://github.com/wolfSSL/wolfssl/pull/10641 - Issue Tracking, Patch
References	~~() https://www.wolfssl.com/docs/security-vulnerabilities/ -~~	() https://www.wolfssl.com/docs/security-vulnerabilities/ - Vendor Advisory
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.5
CPE		cpe:2.3:a:wolfssl:wolfssl::::::::
First Time		Wolfssl wolfssl Wolfssl

25 Jun 2026, 20:22

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-25 20:17

Updated : 2026-06-26 18:54

NVD link : CVE-2026-12340

Mitre link : CVE-2026-12340

CVE.ORG link : CVE-2026-12340

JSON object : View

Products Affected

wolfssl

wolfssl

CWE

CWE-125

Out-of-bounds Read

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