CVE-2026-3849

MEDIUM EPSS 35.4%
Published Mar 19, 20263mo ago · Modified Mar 26, 20263mo ago
6.9 CVSS 4.0
Medium
Find Similar
Published Mar 19, 2026 3mo ago
Last Modified Mar 26, 2026 3mo ago

Description

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 Details

Base Score
6.9
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:D/RE:M/U:Amber
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
35.4% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-787 Out-of-bounds Write Memory Safety

Affected Products 1

VendorProductVersionRange
wolfsslwolfssl*≥5.6.0  –  <5.9.0

References 1

  • github.com https://github.com/wolfSSL/wolfssl/pull/9737
    Issue TrackingPatch

Remediation

  • github.com https://github.com/wolfSSL/wolfssl/pull/9737
    Issue TrackingPatch