cvedb.io
CVE-2026-3849
CRITICAL · CVSS 9.8
EPSS exploitation probability: 0%
Published 2026-03-19T21:17:13.407 · Last modified 2026-06-17T10:44:20.600

Summary

Stack Buffer Overflow in wc_HpkeLabeledExtract via Oversized ECH Config. A vulnerability existed in wolfSSL 5.8.4 ECH (Encrypted Client Hello) support, where a maliciously crafted ECH config could cause a stack buffer overflow on the client side, leading to potential remote execution and client program crash. This could be exploited by a malicious TLS server supporting ECH. Note that ECH is off by default, and is only enabled with enable-ech.

Affected products

wolfssl — wolfssl

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.