High severity · published Sep 27, 2026
CVE-2026-89136
Client accepts unsolicited RawPublicKey server certificate type
8.3
CVSS
0.4%
EPSS
No
On KEV
Description
When using RPK (Raw Public Key), the client side of a TLS 1.2, 1.3 and DTLS 1.2 connection could accept an unsolicited server_cert_type=RawPublicKey which allowed a malicious or misbehaving server to bypass authentication. RPK is off by default and only enabled in --enable-rpk OR --enable-all OR --enable-distro AKA HAVE_RPK builds.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 32% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WO
wolfSSL · wolfSSL
5.6.0 through 5.9.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89136
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-89136
github.com
https://github.com/wolfSSL/wolfssl/pull/11009
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