HIGHVulnerability
Verified
Global

NVD HIGH: CVE-2026-12340 — Out-of-bounds heap read during SM2/SM3 certificate signature verification. When ...

·Source: NIST NVD

Updated:

Executive Summary

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

Analysis

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 Score: 7.5. Published: 2026-06-25T20:17:09.907.

Indicators of Compromise (1)

CVE (1)
CVE-2026-12340
Source Attribution

Originally published by NIST NVD on Jun 25, 2026. Verified by: NIST.

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