libcurl: libcurl: Information disclosure due to failure to clear proxy authentication credentials

A flaw was found in curl. When libcurl is instructed to clear proxy authentication credentials, it fails to do so, leaving the old credentials available. This could lead to the unintended reuse of sensitive proxy authentication credentials for subsequent network transfers, potentially resulting i...

curl: curl: Denial of Service via WebSocket PING flood

A flaw was found in curl. A malicious server can exploit this vulnerability by sending rapid, sequential WebSocket PING messages. Due to a lack of an upper bound on memory allocation for unacknowledged frames, curl can be forced to exhaust all available memory, leading to a denial of service...

libcurl: libcurl: Certificate validation bypass due to incorrect connection reuse

A flaw was found in curl. When libcurl reuses a connection from its connection pool, an easy handle that initially used default native Certificate Authority CA trust may continue to trust the native platform store. This occurs even after the application has switched that same handle to custom CA...

curl: curl: Information disclosure via incorrect .netrc password lookup

A flaw was found in curl. When curl is configured to use a .netrc file for credentials and a URL is provided with a username but no password, curl may incorrectly retrieve and use the password for a different user from the .netrc file for the same host. This could lead to unauthorized information...

curl: curl: Information disclosure via incorrect Digest authentication header reuse

A flaw was found in curl. When libcurl performs a transfer to an HTTP origin using Digest authentication and then reuses the same connection handle for a subsequent transfer to a different origin, it may incorrectly send the authentication header intended for the first origin to the second. This...

curl: curl: SSH host verification bypass when using schemeless URLs with SFTP/SCP

A flaw was found in curl. When a user invokes curl with a schemeless URL and specifies SFTP SSH File Transfer Protocol or SCP Secure Copy Protocol as the default protocol, the tool layer fails to initialize critical SSH security options. This bypasses host verification, allowing curl to connect t...

curl: curl: Insecure connection establishment due to TLS configuration mismatch

A flaw was found in curl. When a new data transfer attempts to upgrade its connection using STARTTLS, it may incorrectly reuse an existing live connection. This reuse can occur even if the Transport Layer Security TLS configuration of the new transfer does not match the existing connection,...

curl: libcurl: curl/libcurl: Remote denial of service via QUIC UDP receive function vulnerability

A flaw was found in curl and libcurl. A malicious HTTP/3 server can exploit an issue in the QUIC UDP receive function by continuously streaming empty UDP datagrams. This can lead to a remote denial of service DoS against a curl or libcurl client, as the helper function discards zero-length UDP...

curl: curl: Cookie injection via malicious HTTP server using super cookies

A flaw was found in curl's cookie parsing logic. A malicious HTTP server can exploit this by setting 'super cookies' that bypass the Public Suffix List check. This allows an attacker-controlled origin to inject cookies that curl then transmits to unrelated third-party domains, leading to...

CURL-CVE-2026-9547 SSH improper host validation

When a libcurl-based application performs transfers via SCP:// or SFTP:// and utilizes the CURLOPTSSHKEYFUNCTION callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for th...

CURL-CVE-2026-8925 SASL double-free

The curl logic that works with SASL authentication could end up cleaning up the GSASL context twice without clearing the pointer in between, making it free the same pointer twice...

CURL-CVE-2026-8924 trailing dot domain super cookie

A flaw in curl’s cookie parsing logic allows a malicious HTTP server to set "super cookies" that bypass the Public Suffix List check. This enables an attacker-controlled origin to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains...

UAF after pause in socket callback

Calling curleasypause within the event-based CURLMOPTSOCKETFUNCTION callback triggers a use-after-free vulnerability, where libcurl attempts to store a flag using a dangling struct pointer immediately after that pointer's memory has been freed...

CURL-CVE-2026-11564 Native CA trust persist

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...

password leak with netrc and user in URL

When asking curl to use a .netrc file to find credentials and at the same time specifying a URL with a username without a password, like https://[email protected]/, curl could wrongly get and use the password for another user set in the .netrc file for that host if such a one exists and there is n...

trailing dot domain super cookie

A flaw in curl’s cookie parsing logic allows a malicious HTTP server to set "super cookies" that bypass the Public Suffix List check. This enables an attacker-controlled origin to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains...

CURL-CVE-2026-8926 password leak with netrc and user in URL

When asking curl to use a .netrc file to find credentials and at the same time specifying a URL with a username without a password, like https://[email protected]/, curl could wrongly get and use the password for another user set in the .netrc file for that host if such a one exists and there is n...

CURL-CVE-2026-11352 QUIC zero-length UDP datagrams busy-loop

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...

CURL-CVE-2026-11586 WS Auto-PONG memory exhaustion

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...

proto-default skips SSH verification

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...