CVE detail
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).
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 13.9 · diversity 15.0 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 3
- within the 30d window
- Peak daily
- 2
- highest bucket
Evidence
Source links by recency
3 source links · newest first
- CVE-2026-12340 Out-of-bounds heap read in SM2/SM3 certificate Subject Key Identifier computationMicrosoft MSRC
Information published.
vendormsrc.microsoft.comJul 1, 2026, 8:05 AM - https://www.wolfssl.com/docs/security-vulnerabilities/www.wolfssl.com
No excerpt available.
Vendor Advisorywww.wolfssl.comJun 25, 2026, 8:17 PM No excerpt available.
Exploitgithub.comJun 25, 2026, 8:17 PM
Exploit code
Public exploit repository references
Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.
0 repository references · best confidence N/A · max 0 stars
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