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.

Reference: https://avd.aquasec.com/nvd/cve-2025-14017

When an OAuth2 bearer token is used for an HTTP(S) transfer, and that transfer performs a cross-protocol redirect to a second URL that uses an IMAP, LDAP, POP3 or SMTP scheme, curl might wrongly pass on the bearer token to the new target host.

Reference: https://avd.aquasec.com/nvd/cve-2025-14524

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.

Reference: https://avd.aquasec.com/nvd/cve-2025-14819

KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web. From 0.11.0 until 0.18.2, KaTeX uses ordinary JavaScript property access for the renderer options object, the trust setting, default and processor setting metadata, and namespace lookup and group restoration, allowing inherited properties to be treated as explicitly supplied values. When Object.prototype is already polluted or an attacker controls the options object's prototype, attacker-controlled mathematical expressions can use an inherited trust value to enable trusted rendering and produce links capable of user-interaction cross-site scripting or loading attacker-selected external resources in a consuming application that inserts unsanitized KaTeX output into a page. KaTeX does not itself create the prototype pollution, and rendering an expression alone does not execute script. This issue is fixed in version 0.18.2.

Reference: https://avd.aquasec.com/nvd/cve-2026-103923

A use-after-free vulnerability exists in libcurl when an application configures an HTTP/2 stream-dependency tree via `CURLOPT_STREAM_DEPENDS` or `CURLOPT_STREAM_DEPENDS_E`, subsequently invokes `curl_easy_reset()`, and finally terminates the handle with `curl_easy_cleanup()`. During this final cleanup phase, libcurl attempts to access and modify an internal structure that was already freed during the reset operation.

Reference: https://avd.aquasec.com/nvd/cve-2026-10536

An issue in curl’s QUIC UDP receive function allows a malicious HTTP/3 server to trigger a remote denial of service against a curl or libcurl client. Because the helper function discards zero-length UDP datagrams before counting them toward the per-call packet budget, a connected QUIC peer can continuously stream empty datagrams to indefinitely stall the client.

Reference: https://avd.aquasec.com/nvd/cve-2026-11352

libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. An easy handle that first uses default native CA trust can continue trusting the native platform store after the application switches that same handle to custom CA material for a later transfer.

Reference: https://avd.aquasec.com/nvd/cve-2026-11564

By default, curl automatically responds to WebSocket PING frames. Because curl lacks an upper bound on memory allocation for unacknowledged frames, a malicious server can exhaust all available memory by flooding curl with rapid, sequential PING messages.

Reference: https://avd.aquasec.com/nvd/cve-2026-11586

Successfully using libcurl to do a transfer to a specific HTTP origin (`hostA`) with **Digest** authentication and then changing the origin to a different one (`hostB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Authorization:` header field meant for `hostA`, to `hostB`.

Reference: https://avd.aquasec.com/nvd/cve-2026-11856

When a user invokes curl using a schemeless URL combined with `--proto-default` sftp (or scp), a disconnect occurs between the tool layer and libcurl. The tool layer incorrectly infers the URL scheme, which erroneously bypasses the initialization of critical SSH security options like CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 and CURLOPT_SSH_KNOWNHOSTS. Conversely, the libcurl runtime successfully honors CURLOPT_DEFAULT_PROTOCOL and establishes the connection via SFTP/SCP as specified. Because the tool layer skipped the security configuration, these SSH host verification options are silently omitted, causing curl to connect to an unverified SSH remote host without throwing an error.

Reference: https://avd.aquasec.com/nvd/cve-2026-12064