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OpenAdvisories
Critical · 9.1 CVE-2026-87866 EUVD-2026-105314GHSA-wq9f-qmpx-2cc8

wolfSSL public-key pinning bypass

Published Oct 20, 2026 · Updated Oct 29, 2026 · Assigned by curl

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.

Affected products

VendorProductAffectedFixed
curl curl 8.22.0 – ≤ 8.22.0, 8.21.0 – ≤ 8.21.0, 8.20.0 – ≤ 8.20.0, 8.19.0 – ≤ 8.19.0, 8.18.0 – ≤ 8.18.0, 8.17.0 – ≤ 8.17.0, 8.16.0 – ≤ 8.16.0, 8.15.0 – ≤ 8.15.0, 8.14.1 – ≤ 8.14.1, 8.14.0 – ≤ 8.14.0, 8.13.0 – ≤ 8.13.0, 8.12.1 – ≤ 8.12.1, 8.12.0 – ≤ 8.12.0, 8.11.1 – ≤ 8.11.1, 8.11.0 – ≤ 8.11.0, 8.10.1 – ≤ 8.1… —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 curl No fix yet —
Debian 13 curl No fix yet —
Debian 12 curl No fix yet —
ReleasePackageFixed inAdvisory
Red Hat Hardened Images 1 curl +3 8.23.0-0.1.hum1 RHSA-2026:82895
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed curl 8.23.0-1.1 openSUSE-SU-2026:12150-1
ReleasePackageFixed inAdvisory
Alpine v3.24 curl 8.23.0-r0 —
Alpine v3.23 curl 8.23.0-r0 —

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 curl +4 No fix yet —

Advisories 3

References