When doing TLS related transfers with reused easy or multi handles and
altering the `CURLSSLOPT_NO_PARTIALCHAIN` option, libcurl could accidentally
reuse a CA store cached in memory for which the partial chain option was
reversed. Contrary to the user's wishes and expectations. This could make
libcurl find and accept a trust chain that it otherwise would not.
CVSS Score
5.3
EPSS Score
0.007
Published
2026-01-08
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 Score
5.9
EPSS Score
0.002
Published
2026-01-08
When doing multi-threaded LDAPS transfers (LDAP over TLS) with libcurl,
changing TLS options in one thread would inadvertently change them globally
and therefore possibly also affect other concurrently setup transfers.
Disabling certificate verification for a specific transfer could
unintentionally disable the feature for other threads as well.
CVSS Score
6.3
EPSS Score
0.001
Published
2026-01-08
curl's code for managing SSH connections when SFTP was done using the wolfSSH
powered backend was flawed and missed host verification mechanisms.
This prevents curl from detecting MITM attackers and more.
CVSS Score
4.3
EPSS Score
0.004
Published
2025-11-07
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