CVE-2026-87866
wolfSSL public-key pinning bypass
No known exploitation. EPSS puts it in the 7th percentile. No fix published yet.
What to do
No fixed build or workaround is published yet. Limit exposure and watch for a patch.
- CurlAffected: ≥ 8.22.0, ≤ 8.22.0Upgrade to: after 8.22.0Affected: ≥ 8.21.0, ≤ 8.21.0Upgrade to: after 8.21.0Affected: ≥ 8.20.0, ≤ 8.20.0Upgrade to: after 8.20.0Affected: ≥ 8.19.0, ≤ 8.19.0Upgrade to: after 8.19.0 + 96 more branchesStated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.2% chance of exploitation activity in the next 30 days, which ranks it in the 7th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
3 events over 2 days, from the signal feeds we watch.
- OpenVAS check added
- Publishedrecord updated
Affected products
Sources
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