CVE-2026-12340
Last modified
CVE-2026-12340 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.21% chance of exploitation in the next 30 days.
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).
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Wolfssl | Wolfssl | >= 5.6.4, < 5.9.2 |
References
- https://github.com/wolfSSL/wolfssl/pull/10641Issue Tracking, Patch
- https://www.wolfssl.com/docs/security-vulnerabilities/Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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