CVE-2026-12340
High
Description
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).
SeverityHigh
CVSS7.5
Exploit probability—
ProductWolfssl
PublishedJun 25, 2026
First seenJun 25, 2026
Weakness typeCWE-125Out-of-bounds read
How to fix
Update
- wolfssl wolfssl5.9.2 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| wolfssl wolfssl | 5.6.4 ≤ v < 5.9.2 | 5.9.2 |
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