CVE-2026-87866: critical vulnerability in curl
wolfSSL public-key pinning bypass
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.1epss 0.5%
When built with wolfSSL, curl can successfully validate a pinned public key
hash against a key the TLS peer does not possess. During the TLS handshake,
wolfSSL validates the connection, but curl's subsequent re-parsing of the same
certificate - tricked by a manipulated validity length field - extracts and
matches a different embedded key, incorrectly authorizing the pinned public
key.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected products
curl · curlRelated CVEs — curl
In the same product, most dangerous first.