Vulnerability · Published Sep 27, 2026 · Assigned by wolfSSL
CVE-2026-89136Client accepts unsolicited RawPublicKey server certificate type
High 8.3
In plain English
A high-severity improper authentication in wolfSSL from wolfSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | wolfssl | 5.9.4-r0 | ALPINE-CVE-2026-89136 |
| Debian:13 | wolfssl | no fix listed | DEBIAN-CVE-2026-89136 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-89136 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-89136 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-89136 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-89136 |
Affected products (as reported)
Weakness: CWE-287 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N