CVE-2026-11352

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...

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...

CVE-2026-10536 HTTP/2 stream-dependency tree UAF

A use-after-free vulnerability exists in libcurl when an application configures an HTTP/2 stream-dependency tree via CURLOPTSTREAMDEPENDS or CURLOPTSTREAMDEPENDSE, subsequently invokes curleasyreset, and finally terminates the handle with curleasycleanup. During this final cleanup phase, libcurl...

EUVD-2026-41497

A use-after-free vulnerability exists in libcurl when an application configures an HTTP/2 stream-dependency tree via CURLOPTSTREAMDEPENDS or CURLOPTSTREAMDEPENDSE, subsequently invokes curleasyreset, and finally terminates the handle with curleasycleanup. During this final cleanup phase, libcurl...

CVE-2026-10536

A use-after-free vulnerability exists in libcurl when an application configures an HTTP/2 stream-dependency tree via CURLOPTSTREAMDEPENDS or CURLOPTSTREAMDEPENDSE, subsequently invokes curleasyreset, and finally terminates the handle with curleasycleanup. During this final cleanup phase, libcurl...

Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : curl vulnerabilities (USN-8487-1)

The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8487-1 advisory. Andrew Nesbitt discovered that curl could reuse an existing live connecti...

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: 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: 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: Man-in-the-middle attack via SSH host key bypass

A flaw was found in curl. When a libcurl-based application uses SCP:// or SFTP:// for transfers and employs the CURLOPTSSHKEYFUNCTION callback, it may silently accept an untrusted server. This occurs if the server's host key type differs from the one stored in the knownhosts file. The callback...

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: 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: 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: Use-after-free via curl_easy_pause() in CURLMOPT_SOCKETFUNCTION callback

A flaw was found in libcurl. When curleasypause is called within the event-based CURLMOPTSOCKETFUNCTION callback, a use-after-free vulnerability is triggered. This occurs because libcurl attempts to store a flag using a pointer to memory that has already been freed. An attacker could potentially...

curl: curl: Double-free vulnerability in SASL authentication

A flaw was found in curl. The logic handling SASL Simple Authentication and Security Layer authentication could lead to a double-free vulnerability. This occurs because the GSASL context may be deallocated twice without clearing the pointer, potentially leading to memory corruption. An attacker...

USN-8487-1: curl vulnerabilities

Andrew Nesbitt discovered that curl could reuse an existing live connection during STARTTLS-based connection upgrades even when the TLS configuration did not match. A remote attacker could possibly use this issue to cause curl to use an unintended TLS configuration. CVE-2026-8286 Muhamad Arga...

mariadb: Arbitrary shell command execution via improper sanitization in CONNECT engine

A flaw was found in MariaDB server. When the CONNECT engine is installed and REST support is enabled on Windows, a user can exploit improper sanitization of the table HTTP attribute. This attribute is interpolated into the curl command line, allowing for arbitrary shell command execution on the...

mariadb: Arbitrary shell command execution via improper sanitization in CONNECT engine

A flaw was found in MariaDB server. When the CONNECT engine is installed and REST support is enabled on Windows, a user can exploit improper sanitization of the table HTTP attribute. This attribute is interpolated into the curl command line, allowing for arbitrary shell command execution on the...

SUSE-SU-2026:2703-1 Security update for curl

This update for curl fixes the following issues - CVE-2026-4873: connection reuse ignores TLS requirement bsc1262631. - CVE-2026-5545: wrong reuse of HTTP Negotiate connection bsc1262632. - CVE-2026-5773: wrong reuse of SMB connection bsc1262633. - CVE-2026-6253: proxy credentials leak over...

mariadb: Arbitrary shell command execution via improper sanitization in CONNECT engine

A flaw was found in MariaDB server. When the CONNECT engine is installed and REST support is enabled on Windows, a user can exploit improper sanitization of the table HTTP attribute. This attribute is interpolated into the curl command line, allowing for arbitrary shell command execution on the...