When using `CURLOPT_PINNEDPUBLICKEY` option with libcurl or `--pinnedpubkey` with the curl tool, curl should check the public key of the server certificate to verify the peer.
This check was skipped in a certain condition that would then make curl allow the connection without performing the proper check, thus not noticing a possible impostor. To skip this check, the connection had to be done with QUIC with ngtcp2 built to use GnuTLS and the user had to explicitly disable the standard certificate verification.
CVSS Details
- CVSS 3.1 Base Score: 5.9
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade curl | Jun 18, 2026 | Jan 8, 2026 |
| Debian | — | Upgrade curl | Jul 23, 2026 | Jul 23, 2026 |
| Freebsd | — | Upgrade curl | Mar 12, 2026 | Mar 11, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Jan 7, 2026 |
| Ubuntu | — | Upgrade libcurl3-gnutlsUpgrade libcurl3t64-gnutlsUpgrade libcurl4t64Upgrade libcurl4-gnutls-devUpgrade libcurl4-openssl-devUpgrade libcurl4-nss-devUpgrade libcurl4Upgrade libcurl3-nssUpgrade curl | Feb 26, 2026 | Feb 25, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | May 27, 2026 | Jan 8, 2026 |
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