CVE-2026-55960

HIGH
Published Jun 25, 2026 Modified Jun 26, 2026 CWE-295

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.

CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS — Exploit Prediction

0.0015
Probability of exploitation
0.04%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-295 CWE-295

Affected Products

Vendor Product
wolfssl wolfssl

References

Frequently Asked Questions

What is CVE-2026-55960? +
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. It has a CVSS v3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-55960? +
CVE-2026-55960 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-55960? +
CVE-2026-55960 affects products from wolfssl, specifically: wolfssl. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-55960? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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