Items to be removed from future curl releases

If any of these deprecated features is a cause for concern for you, please email the curl-library mailing list as soon as possible and explain to us why this is a problem for you and how your use case cannot be satisfied properly using a workaround.

Windows XP

In January 2026, curl drops support for Windows XP and Server 2003. Their "mainstream support" ended in 2014, with final updates on May 14, 2019.

Making the new minimum target Windows version Vista / Server 2008.

c-ares 1.16.0

In March 2026, we drop support for all c-ares versions before 1.16.0.

OpenSSL-QUIC

OpenSSL-QUIC is what we call the curl QUIC backend that uses the OpenSSL QUIC stack.

• It is slower and uses more memory than the alternatives and is only experimental in curl.
• It gets little attention from OpenSSL and we have no expectation of the major flaws getting corrected anytime soon.
• No one has spoken up for keeping it
• curl users building with vanilla OpenSSL can still use QUIC through the means of ngtcp2

We remove the OpenSSL-QUIC backend in January 2026.

RTMP

RTMP in curl is powered by the 3rd party library librtmp.

• RTMP is barely used by curl users (2.2% in the 2025 survey)
• librtmp has no test cases, makes no proper releases and has not had a single commit within the last year
• librtmp parses the URL itself and requires non-compliant URLs for this
• we have no RTMP tests

Support for RTMP in libcurl gets removed in April 2026.

CMake 3.17 and earlier

We remove support for CMake <3.18 in April 2026.

CMake 3.18 was released on 2020-07-15.

Past removals

• axTLS (removed in 7.63.0)
• Pipelining (removed in 7.65.0)
• PolarSSL (removed in 7.69.0)
• NPN (removed in 7.86.0)
• Support for systems without 64-bit data types (removed in 8.0.0)
• NSS (removed in 8.3.0)
• gskit (removed in 8.3.0)
• MinGW v1 (removed in 8.4.0)
• NTLM_WB (removed in 8.8.0)
• space-separated NOPROXY patterns (removed in 8.9.0)
• hyper (removed in 8.12.0)
• Support for Visual Studio 2005 and older (removed in 8.13.0)
• Secure Transport (removed in 8.15.0)
• BearSSL (removed in 8.15.0)
• msh3 (removed in 8.16.0)
• winbuild build system (removed in 8.17.0)
• Windows CE (removed in 8.18.0)
• Support for Visual Studio 2008 (removed in 8.18.0)
• OpenSSL 1.1.1 and older (removed in 8.18.0)