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...

CURL-CVE-2026-8932 incomplete mTLS config matching in conn reuse

libcurl would reuse a previously created connection even when some mTLS config related option had been changed that should have prohibited reuse. libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. However, some TLS...

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...

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...

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...

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-2026-11564 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...

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-2026-9547 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-2026-9545 exposing HTTP/3 early data

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL...

Linux Distros Unpatched Vulnerability : CVE-2026-11564

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - 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 use...

PT-2026-51747

Name of the Vulnerable Software and Affected Versions curl affected versions not specified Description A flaw in the 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...

PT-2026-51748

Name of the Vulnerable Software and Affected Versions curl affected versions not specified Description The logic handling SASL Simple Authentication and Security Layer authentication may clean up the GSASL context twice without clearing the pointer in between. This results in a double-free...

PT-2026-51753

Name of the Vulnerable Software and Affected Versions libcurl affected versions not specified Description A use-after-free issue occurs when the curl easy pause function is called within the event-based CURLMOPT SOCKETFUNCTION callback. This leads to a situation where libcurl attempts to store a...

Linux Distros Unpatched Vulnerability : CVE-2026-8932

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - libcurl would reuse a previously created connection even when some mTLS config related option had been changed that should have prohibited reuse. libcurl keeps...

Linux Distros Unpatched Vulnerability : CVE-2026-50019

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - yt-dlp is a command-line audio/video downloader. From 2023.09.24 until 2026.06.09, if curl is used as an external downloader for yt-dlp, cookies may be leaked t...

Linux Distros Unpatched Vulnerability : CVE-2026-9547

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - When a libcurl-based application performs transfers via SCP:// or SFTP:// and utilizes the CURLOPTSSHKEYFUNCTION callback, it may silently accept an untrusted...

Linux Distros Unpatched Vulnerability : CVE-2026-9080

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Calling curleasypause within the event-based CURLMOPTSOCKETFUNCTION callback triggers a use- after-free vulnerability, where libcurl attempts to store a flag...

Linux Distros Unpatched Vulnerability : CVE-2026-9545

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced...

Linux Distros Unpatched Vulnerability : CVE-2026-9079

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - libcurl had a flaw that when instructed to clear proxy authentication credentials which made it not do so, leaving the old credentials around to get used for...