CVE-2026-12340 Affecting wolfssl package, versions <5.9.2-1


Severity

Recommended
low

Based on Debian security rating.

Threat Intelligence

EPSS
0.23% (14th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-WOLFSSL-18321110
  • published27 Jul 2026
  • disclosed25 Jun 2026

Introduced: 25 Jun 2026

CVE-2026-12340  (opens in a new tab)

How to fix?

Upgrade Debian:unstable wolfssl to version 5.9.2-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream wolfssl package and not the wolfssl package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

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).