CVE-2026-87866
When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the…
- Risk score
- 62/100
- CVSS
- 9.1 v3.1
- Exploit chance (30 days)
- 0.2%
- Published
- 20 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 di…
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Amber
- CVSS 9.1 critical
- Remotely exploitable without logging in
References
Original description
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.
Last activity 20 Oct 2026. Patch Forecast updates every hour.