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Critical 9.3Published Jan 7, 2026

CVE-2025-15346wolfSSL Python library `CERT_REQUIRED` mode fails to enforce client certificate requirement

Updated under an hour ago ()

Does this affect you?

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

No exploitation reported and no EPSS estimate yet.

A vulnerability in the handling of verify_mode = CERT_REQUIRED in the wolfssl Python package (wolfssl-py) causes client certificate requirements to not be fully enforced.  Because the WOLFSSL_VERIFY_FAIL_IF_NO_PEER_CERT flag was not included, the behavior effectively matched CERT_OPTIONAL: a peer certificate was verified if presented, but connections were incorrectly authenticated when no client certificate was provided.  This results in improper authentication, allowing attackers to bypass mutual TLS (mTLS) client authentication by omitting a client certificate during the TLS handshake.  The issue affects versions up to and including 5.8.2.

CVSS
9.3 CRITICAL (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/AU:Y
Weakness (CWE)
CWE-306, CWE-287
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
Deferred
Record last updated
Jan 8, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
wolfSSL wolfSSL-py
wolfssl:py (from the name)
from 5.3.0 through 5.8.2
CNA record

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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