libmicrohttpd

HTTP/1.x server C library (MHD 1.x, stable)
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NEWS (18207B)


      1 Thu Apr 16 10:36:54 AM CEST 2026
      2 Released GNU libmicrohttpd 1.0.5.
      3 
      4     This is a bugfix release.
      5     It fixes a additional HTTP request smuggling issues (CWE-444).
      6 
      7     -- Christian Grothoff
      8 
      9 Mon Apr 13 11:42:06 AM CEST 2026
     10 Released GNU libmicrohttpd 1.0.4.
     11 
     12     This is a bugfix release.
     13     It fixes a minor HTTP request smuggling issue (CWE-444).
     14 
     15     -- Christian Grothoff
     16 
     17 Thu Apr  2 12:16:28 AM CEST 2026
     18 Released GNU libmicrohttpd 1.0.3.
     19 
     20     This is a bugfix release.
     21     It primarily fixes a list traversal issue that could
     22     cause connection handling issues when other connections
     23     were suspended.
     24 
     25     -- Christian Grothoff
     26 
     27 Mon Jul 14 2025 05:03:07 PM CEST
     28 Released GNU libmicrohttpd 1.0.2.
     29 
     30     This is a bugfix release.
     31     It primarily fixes a double-close() bug on bind() errors.
     32 
     33     -- Christian Grothoff
     34 
     35 Fri 23 Feb 2024 21:00:00 UZT
     36 Released GNU libmicrohttpd 1.0.1.
     37 
     38     This is a correction release.
     39     This release mainly fixes and improves builds with non-default configure
     40     parameters.
     41 
     42     -- Evgeny Grin (Karlson2k)
     43 
     44 Thu 01 Feb 2024 15:00:00 CET
     45 Released GNU libmicrohttpd 1.0.0.
     46 
     47     This is the first non-bugfix release since version 0.9.75 and the first
     48     ever stable release of GNU libmicrohttpd. It is a huge one with new
     49     features and fixes.
     50 
     51     The major changes:
     52     * Rewritten parsing of clients' requests, fully aligned with current
     53       RFCs (9110 and 9112) requirements. Added detailed control of strict
     54       or lenient specification enforcement. Application may choose between
     55       more compatible mode or more strict and secure mode.
     56     * Reworked Digest Auth, greater enhanced support for current RFC 7617
     57       features. MHD currently is the only known server-side implementation
     58       with support for SHA-512/256, userhash and username in extended
     59       notation. At the same time the very old RFC2069 is supported, as
     60       well as MD5 and SHA-256.
     61     * Improved functionality in multi-threading environment, especially with
     62       external sockets polling modes.
     63     * Reworked Basic Auth, adding new convenient API functions.
     64     * Re-implemented GnuTLS initialisation. Now supported
     65       libmicrohttpd-specific system-wide configuration, as well as generic
     66       GnuTLS system-wide configuration. Application may adjust settings based
     67       on system configuration instead of specifying its own full
     68       configuration.
     69     * Tons of other new functionality and various fixes. For detailed changes
     70       see the ChangeLog or Git commit logs.
     71 
     72 
     73     Since last non-bugfix release there are 1062 commits added with
     74     67007 lines insertions and 26616 deletions.
     75 
     76     -- Evgeny Grin (Karlson2k)
     77 
     78 Sun 28 May 2023 18:00:00 MSK
     79 Released GNU libmicrohttpd 0.9.77.
     80 
     81     This is mostly a bugfix release.
     82     This version created by taking patches from the current development
     83     branch and back-porting them on top of version 0.9.76.
     84     The most notable changes are: some improvements for Digest and Basic
     85     authorizations, fixed efficiency for TLS upgraded connections, fixed
     86     processing of folded headers in requests, fixed functionality with
     87     blocking sockets, improved and fixed internal test-suite.
     88 
     89     The more detailed list of the important changes:
     90 
     91     API changes:
     92     + Added new function MHD_get_version_bin().
     93 
     94     Improvements and enhancements:
     95     * Digest Auth: changed algorithm identifiers in server generated
     96       headers from "md5" / "sha-256" to "MD5" / "SHA-256" to better match
     97       RFC (while clients should use caseless matching).
     98     * Improved Base64 decoding by new implementation with robust input
     99       data validation checks.
    100     * Improved configure for cross-compiling, for better compatibility
    101       with POSIX and for better compatibility with the latest compiler
    102       versions.
    103     * New internal tests: for Base64 decoding, Basic Auth and folded
    104       headers.
    105     * Supported new libcurl API in tests to mute deprecation warnings.
    106     * Supported ARM and ARM64 for VC compilers.
    107 
    108     Functionality changes:
    109     * any negative number returned by response data generation callback
    110       function is treated as an error. Previously negative values except
    111       predefined error codes could produce undefined behaviour.
    112     * Added handling of "DEBUG" preprocessor macro as an alias of "_DEBUG".
    113 
    114     Fixes:
    115     # Fixed functionality with blocking sockets.
    116     # Fixed very inefficient data pumping for upgraded TLS connections.
    117     # Fixed processing of folded headers in the requests.
    118     # Fixed data races when closing upgraded connection.
    119     # Removed duplication of "Connection: upgrade" header.
    120     # Digest auth: fixed thread sync to avoid "stale hash" results.
    121     # Fixed harmless unwanted extra data processing resulting in triggering
    122       of the assert.
    123     # Fixed tests for LTO.
    124     # Removed removed non-portable functions in examples.
    125     # Fixed delayed call of connection notification callback in
    126       thread-per-connection mode.
    127     # Fixed Address Sanitizer unpoison of memory when memory pool is
    128       destroyed. This fixed periodic ASAN error when used for a long time
    129       with the sanitizer.
    130     # Fixed compiler warnings in library code, examples, tests and configure
    131       checks.
    132     # New TLS certificates for test-suite: all with SAN fields and SHA-256
    133       hash.
    134     # Tests: fixed tests on Darwin 22.x (Ventura).
    135     # Tests: redesigned one tests group to avoid stress-testing of the OS.
    136 
    137     -- Evgeny Grin (Karlson2k)
    138 
    139 Sun 26 Feb 2023 17:49:30 CET
    140 Released GNU libmicrohttpd 0.9.76 hotfix. -CG
    141 
    142     This is a hotfix release.
    143     This only change since previous release is fixed potential DoS vector
    144     in MHD_PostProcessor discovered by Gynvael Coldwind and Dejan
    145     Alvadzijevic (CVE-2023-27371).
    146     While the researchers have not been able to exploit this attack vector
    147     when libmicrohttpd is compiled with the standard GNU C library, it is
    148     recommended that you update MHD as soon as possible if your
    149     applications are using (optional) MHD_PostProcessor functionality.
    150 
    151     -- Evgeny Grin (Karlson2k)
    152 
    153 Sun 26 Dec 2021 20:30:00 MSK
    154 Released GNU libmicrohttpd 0.9.75 -EG
    155 
    156     This is a correction release.
    157     The main improvement is the implementation of workaround for some
    158     OSes (like OpenBSD 7) where "monotonic" clock may jump back. Now
    159     MHD is able to automatically detect such situation and recover if
    160     the jump is small. This workaround is needed with increased
    161     accuracy of connection timeout introduced in previous version, as
    162     with lower accuracy (v0.9.73 and before) these jumpbacks were
    163     unnoticeable.
    164     Other changes: fixed some compiler, Makefile, and configure
    165     warnings on specific platforms; one test further improved.
    166 
    167     -- Evgeny Grin (Karlson2k)
    168 
    169 
    170 Sun 19 Dec 2021 18:30:00 MSK
    171 Released GNU libmicrohttpd 0.9.74
    172 
    173     This release brings a lot of fixes and improvements, and
    174     important new features.
    175     The most significant addition is the new experimental
    176     implementation of WebSockets contributed by David Gausmann. This
    177     implementation is not fully tested yet so currently it is disabled
    178     by default.
    179     Other changes include a lot of improvements and clarifications
    180     in doxy comments in microhttpd.h header file, improved compliance
    181     with the RFC HTTP specifications, the new implementation of reply
    182     header forming, the new implementation of request chunked encoding
    183     parsing, new automatic error replies, internal optimisations, and
    184     many important fixes, including fixes for long-standing bugs.
    185 
    186     More detailed list of notable changes:
    187 
    188     API changes:
    189     + Added new function MHD_get_reason_phrase_len_for().
    190     + Added MHD_CONNECTION_INFO_HTTP_STATUS type of information
    191       queried by MHD_get_connection_info().
    192     + Added new response flag MHD_RF_SEND_KEEP_ALIVE_HEADER to force
    193       sending of "keep-alive" header even if not required by RFC.
    194     + Added new response creation function
    195       MHD_create_response_from_buffer_with_free_callback_cls() with
    196       custom cleanup callback.
    197     + Added new response flag MHD_RF_HTTP_1_0_COMPATIBLE_STRICT with
    198       the same functionality as existing MHD_RF_HTTP_VERSION_1_0_ONLY
    199       flag. The old flag will be deprecated.
    200     + Added new response flag MHD_RF_HTTP_1_0_SERVER with the same
    201       functionality as existing MHD_RF_HTTP_VERSION_1_0_RESPONSE flag.
    202       The old flag will be deprecated.
    203 
    204     New features:
    205     + Added experimental WebSockets extension with separate header.
    206       Disabled by default as it is not fully tested yet.
    207     + Added '--enable-sanitizers[=address,undefined,leak,user-poison]'
    208       configure parameter (instead of '--enable-sanitizer'),
    209       implemented custom memory poisoning for memory pools.
    210 
    211     Improvements and enhancements:
    212     * Doxy function descriptions was corrected, clarified, extended,
    213       and improved. Now it should be much easier to learn MHD just by
    214       reading the headers.
    215     * Completely rewritten reply header forming. New implementation is
    216       more robust, simpler maintainable and expandable, and better
    217       follows RFC HTTP specifications.
    218     * Performance improvements: now HTTP version and request method are
    219       decoded one time only (previously MHD used string comparison many
    220       times during processing the data).
    221     * Rewritten request chunked payload decoding. The new
    222       implementation better conforms to the HTTP RFC, detects format
    223       problems earlier, replies to the clients with description of
    224       detected problems, handles untypical (but syntactically correct)
    225       values properly.
    226     * Added special replies for wrong/unsupported HTTP versions in
    227       requests, broken HTTP chunked encoding in requests,
    228     * As required by HTTP RFC, added automatic error replies if client
    229       used broken chunked encoding, too large chunk size, too large
    230       payload size, or broken Content-Length header.
    231     * Optimized connection's memory pool handling.
    232     * Changed timeout precision from one second to one millisecond.
    233     * Added some checks for incorrect user data, reporting problems in
    234       MHD log.
    235     * Improved performance of hash calculations functions by using
    236       compiler built-ins (if available).
    237     * Implemented SHA-1 calculations (required for WebSockets).
    238     * Added universal MSVC project that works with any (sufficiently
    239       new) version of MSVC.
    240     * Developed simple HTTP client to test MHD under very special
    241       conditions.
    242     * Implemented 45 new tests.
    243     * Improved existing tests to test more aspects of MHD.
    244     * Added check for correct results of system and libcurl functions.
    245     * Response headers are checked during forming of responses.
    246     * HTTPS tests were improved.
    247     * Added rebuild on W32 of all required files if files are missing.
    248     * Many internal optimisations and improvements.
    249 
    250     Functionality changes:
    251     * Keep-alive header is omitted by default for HTTP/1.1 connections.
    252       Use of header can be enforced by response flag.
    253     * Chunked encoding is used for HTTP/1.1 non-keep-alive connections
    254       for responses with unknown size. Previously MHD used "indication
    255       of the end of the response by closing connection" in such cases,
    256       however it is not correct for HTTP/1.1 connections as per HTTP
    257       RFC.
    258     * As required by HTTP RFC, use HTTP/1.1 version instead of HTTP/1.0
    259       in reply headers when client is HTTP/1.0 . HTTP/1.0 version can
    260       be enforced by response flag.
    261     * User response headers are used in replies in the same order as
    262       was added by application.
    263     * Allowed tab characters in response header values.
    264     * All custom "Connection:" response headers are automatically
    265       combined into single "Connection:" header.
    266     * "keep-alive" token silently dropped from custom "Connection:"
    267       response header. "Keep-alive" cannot be enforced and used
    268       automatically if possible.
    269     * Allow tab character in custom response header value.
    270     * Disallow space character in custom response header value.
    271     * Do not allow responses with 1xx codes for HTTP/1.0 requests.
    272     * Detected and reported incorrect "Upgrade" responses.
    273     * W32 targets are changed to Vista+ by default. XP is supported
    274       still.
    275 
    276     Fixes:
    277     # Fixed short busy-waiting (up to one second) when connection is
    278       going to be expired and closed.
    279     # Fixed handling of errors during start of new connection, fixed
    280       inability to accept new connections in thread-per-connection mode
    281       due to the missing decrement of number of daemon's connections if
    282       start of new thread is failed.
    283     # Fixed incorrect parsing of LFLF, LFCR, CRCR, and bare CR as
    284       single linefeed in request header and request chunked payload.
    285       Now only CRLF or bare LF are recognized as linefeed.
    286     # Fixed response chunked encoding handling. Now it works properly
    287       with non-keep-alive connection, with fixed size replies (if
    288       chunked was enforced by header), and in other situations.
    289     # Other fixes for chunked replies.
    290     # Fixed handling of custom connection timeout in thread-per-
    291       connection mode.
    292     # Fixed wrongly used MHD_REQUEST_TERMINATED_COMPLETED_OK code for
    293       application notification when MHD_REQUEST_TERMINATED_WITH_ERROR
    294       code must be used.
    295     # Fixed code MHD_REQUEST_TERMINATED_READ_ERROR not reported (code
    296       MHD_REQUEST_TERMINATED_WITH_ERROR was incorrectly used instead).
    297     # Fixed handling of request chunked encoding with untypical
    298       formatting.
    299     # Fixed processing of last part of hex-encoded values under
    300       certain conditions.
    301     # Fixed value returned for MHD_CONNECTION_INFO_REQUEST_HEADER_SIZE.
    302     # Fixed returned value for MHD_FEATURE_AUTOSUPPRESS_SIGPIPE on W32,
    303       now it is MHD_YES as W32 does not need SIGPIPE suppression.
    304     # Fixed portability of bitwise NOT for enums values.
    305     # Fixed SHA-256 and MD5 calculations with unaligned data.
    306     # Fixed incorrect caseless matching for HTTP version.
    307     # Fixed incorrect caseless matching for request method.
    308     # Fixed compatibility with old GnuTLS versions.
    309     # Fixed compiler warnings on 32-bits platforms.
    310     # Fixed blocking sockets setting in tests and examples for W32.
    311     # Fixed examples to really use libmagic if present.
    312     # HTTPS tests were fixed.
    313     # Fixed libcurl test with case-insensitive match for HTTP methods,
    314       method names must use case-sensitive match.
    315     # Fixed tests compatibility with old libcurl versions.
    316     # Fixed build on W32 with llvm-dlltool (this tool is too
    317       oversimplified)
    318 
    319     -- Evgeny Grin (Karlson2k)
    320 
    321 
    322 Sun 25 Apr 2021 14:00:00 MSK
    323 Released GNU libmicrohttpd 0.9.73
    324 
    325     This release brings new features, improvements, and a few fixes.
    326     The most important addition is the new function for vector-backed
    327     responses, based on the patch contributed by NASA engineers.
    328     Other changes include compatibility with autoconf 2.70+, improved
    329     testsuite compatibility with CI systems, fixed and improved MSVC
    330     builds, and implementation of ALPN support.
    331 
    332     More detailed list of notable changes:
    333 
    334     API changes:
    335     + Added new function MHD_create_response_from_iovec(), based on the
    336       patch provided by Lawrence Sebald and Damon N. Earp from NASA.
    337     + Added MHD_OPTION_SIGPIPE_HANDLED_BY_APP daemon option.
    338     + Added new function MHD_run_wait().
    339     + Added MHD_OPTION_TLS_NO_ALPN to disable usage of ALPN even if
    340       it is supported by TLS library.
    341 
    342     New features:
    343     + Added '--enable-heavy-tests' configure parameter (disabled by
    344       default).
    345     + Implemented support for ALPN.
    346 
    347     Improvements and enhancements:
    348     * Return timeout of zero also for connections awaiting cleanup.
    349     * Compatibility with autoconf >=2.70, used new autoconf features.
    350     * Warn user when custom logger option is not the first option.
    351     * Added information to the header about minimal MHD version when
    352       particular symbols were introduced.
    353     * Updated test certificates to be compatible with modern browsers.
    354     * Added on-fly detection of UNIX domain sockets and pipes, MHD does
    355       not try to use TCP/IP-specific socket options on them.
    356     * Report more detailed error description in the MHD log for send
    357       and receive errors.
    358     * Enabled bind port autodetection for MSVC builds.
    359 
    360     Fixes:
    361     # Fix PostProcessor to always properly stop iteration when
    362       application callback tells it to do so.
    363     # Fixed MD5 digest authorization broken when compiled without
    364       variable length arrays support (notably with MSVC).
    365     # Fixed detection of type of send errors on W32.
    366 
    367     -- Evgeny Grin (Karlson2k)
    368 
    369 
    370 Mon 28 Dec 2020 21:36:00 MSK
    371 Released GNU libmicrohttpd 0.9.72
    372 
    373     This release is mostly a bugfix release, with greatly improved
    374     compatibility with various OSes/kernels, including FreeBSD, Windows,
    375     OpenBSD, NetBSD, Darwin (macOS), Solaris. Performance is improved,
    376     especially with HTTPS connections and stay-alive HTTP connections.
    377 
    378     Notable changes since version 0.9.71:
    379 
    380     API changes:
    381     + New function MHD_create_response_from_pipe()
    382 
    383     Improvements and enhancements:
    384     * Fully rewritten code for buffering/pushing from kernel network buffers
    385       for compatibility with various OSes. Reduced number of additional
    386       sys-calls, network is better utilized, responses are delivered faster.
    387     * Restored optimal sendfile() usage on FreeBSD.
    388     * MHD now takes care about SIGPIPE handling by blocking it in internal
    389       threads and avoiding functions (like sendfile()) that could generate
    390       SIGPIPE when blocking of this signal is not possible.
    391 
    392     Fixes:
    393     # Fixed crash in PostProcessor.
    394     # Fixed several resources leaks in corner cases.
    395     # Improved thread sync, thread safety and fixed one use-after-free under
    396       special conditions during stopping of daemon.
    397     # Updated HTTP status codes, header names and methods from the
    398       registries.
    399     # Fixed functioning without listen socket and with internal threads.
    400     # Fixed streaming of chunked responses for both HTTP and HTTPS.
    401     # Various compatibility fixes.
    402 
    403     -- Evgeny Grin (Karlson2k)
    404 
    405 
    406 Tue Jan  9 20:52:48 MST 2007
    407 	Project posted.