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Medium 6.9Published Mar 19, 2026

CVE-2026-3849Buffer Overflow in HPKE via Oversized ECH Config

Updated under an hour ago ()

Does this affect you?

It affects wolfSSL Inc. wolfSSL. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
6.9 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/V:D/RE:M/U:Amber
Weakness (CWE)
CWE-787
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
wolfSSL
NVD analysis
Analyzed
Record last updated
Mar 25, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
wolfSSL Inc. wolfSSL
wolfssl:wolfssl (from the name)
from v5.6.0-stable through v5.8.4-stable
CNA record
wolfssl wolfssl
wolfssl:wolfssl
from 5.6.0 before 5.9.0
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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