CVE-2026-55960 Un-negotiated Raw Public Key (RFC 7250) accepted in place of X.509, bypassing chain validation
Attackers can bypass certificate chain validation by sending un-negotiated raw public keys in wolfSSL builds with RPK support enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55960?
CVE-2026-55960 is a high-severity vulnerability in Wolfssl Wolfssl, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Un-negotiated Raw Public Key (RFC 7250) accepted in place of an X.509 certificate, bypassing chain validation. A raw public key has no chain, so ParseCertRelative() accepts it without performing any trust verification; it must therefore only be accepted when RPK was actually negotiated for that peer. The check now defaults the expected type to X.509 (per RFC 7250/8446) when no type was negotiated, comparing against the received server certificate type on the client and the selected client certificate type on the server, and rejects any mismatch, including an un-negotiated raw public key, with UNSUPPORTED_CERTIFICATE. Only affects builds with Raw Public Key support (HAVE_RPK) enabled - disabled by default in a standalone build, but included in --enable-all.
Weakness: CWE-295
Which versions are affected by CVE-2026-55960?
It affects 1 product.
Products include Wolfssl Wolfssl.
How do I fix CVE-2026-55960?
Apply the vendor's patch.
Is CVE-2026-55960 being exploited?
There is no known exploitation of CVE-2026-55960 in the wild and no public exploit code.
Other vulnerabilities in Wolfssl Wolfssl
Sources
Also known as DEBIAN-CVE-2026-55960, GHSA-58fj-7xwc-45hq, JLSEC-2026-735, UBUNTU-CVE-2026-55960.