VDB
CVE-2026-87866
CVE-2026-87866
PUBLISHED
CVSS 9.1 CRITICAL
Reported by curl · Published October 20, 2026
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.
Risk Scores
CVSS 3.1
9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| curl | curl | 8.22.0, 8.21.0, 8.20.0 |
| alpine | curl | 0 |
| curl | curl | 8.22.0, 8.21.0, 8.20.0 |
Timeline
- CVE Published
- Oct 14, 2026 PoC Published
- Oct 21, 2026 EPSS Score
- Oct 25, 2026 EPSS Score
- Oct 27, 2026 EPSS Score
- Oct 30, 2026 EPSS Score