CVE-2026-87866— wolfSSL public-key pinning bypass
Quick assessment
Affected
curl curl
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
当使用 wolfSSL 构建时，curl 能够成功将一个固定的公钥哈希与 TLS 对等方实际上并不持有的密钥进行验证。在 TLS 握手过程中，wolfSSL 会验证连接，但随后 curl 对同一证书进行重新解析时，因被操纵的有效期长度字段所误导，提取并匹配了一个不同的嵌入密钥，从而错误地授权了该固定的公钥。
Possible ATT&CK Techniques 1 AI
T1572 · Protocol Tunneling
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I. Basic Information for CVE-2026-87866
Vulnerability Information
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Vulnerability Title
wolfSSL public-key pinning bypass
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Affected Products
II. Public POCs for CVE-2026-87866
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
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Vendor Advisories for CVE-2026-87866 (2)
Other References for CVE-2026-87866 (1)
Same Patch Batch · curl · 2026-10-20 · 23 CVEs total
| CVE-2026-92389 | TFTP direction confusion | |
| CVE-2026-107928 | info leak uploading over WebSockets with GnuTLS | |
| CVE-2026-107929 | local interface connection reuse mixup | |
| CVE-2026-94266 | password leak in CURLINFO_EFFECTIVE_URL | |
| CVE-2026-94265 | Authorization: Negotiate sent to foreign origin | |
| CVE-2026-86415 | auto client cert connection reuse mixup | |
| CVE-2026-86414 | leaking host credentials to HTTP proxy | |
| CVE-2026-92390 | -J no-clobber guarantee bypassed with 103 early hints | |
| CVE-2026-92387 | never-ending loop via server response omission | |
| CVE-2026-92388 | FTP wildcard write callback mixup | |
| CVE-2026-92386 | server-set cookie aborts cookie jar load | |
| CVE-2026-86409 | stale SigV4 headers sent unintended | |
| CVE-2026-92391 | curl_mime_free stack overflow by recursion | |
| CVE-2026-87865 | knownhost callback mismatches key as missing | |
| CVE-2026-87864 | IMAP APPEND plus CRLF conversion command injection | |
| CVE-2026-87863 | HSTS response erases persisted entries | |
| CVE-2026-87861 | cross-origin reuse of a Negotiate connection | |
| CVE-2026-87862 | HSTS cache import drops longer-lived child | |
| CVE-2026-86411 | FTP connection reuse inherits client-certificate | |
| CVE-2026-86412 | server-set cookie erases cookie jar |
Showing top 20 of 23 CVEs. View all on vendor page → →