HAProxy - Load balancer
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Amaury Denoyelle 05a295441c BUG/MAJOR: h3: check body size with content-length on empty FIN
In QUIC, a STREAM frame may be received with no data but with FIN bit
set. This situation is tedious to handle and haproxy parsing code has
changed several times to deal with this situation. Now, H3 and H09
layers parsing code are skipped in favor of the shared function
qcs_http_handle_standalone_fin() used to handle the HTX EOM emission.

However, this shortcut bypasses an important HTTP/3 validation check on
the received body size vs the announced content-length header. Under
some conditions, this could cause a desynchronization with the backend
server which could be exploited for request smuggling.

Fix HTTP/3 parsing code by adding a call to h3_check_body_size() prior
to qcs_http_handle_standalone_fin() if content-length header has been
found. If the body size is incorrect, the stream is immediately resetted
with H3_MESSAGE_ERROR code and the error is forwarded to the stream
layer.

Thanks to Martino Spagnuolo for his detailed report on this issue and
for having contacting us about it via the security mailing list.

This must be backported up to 2.6.
2026-03-19 10:38:46 +01:00
.github CI: remove redundant "halog" compilation 2026-02-23 11:11:26 +01:00
addons MINOR: promex: export "haproxy_sticktable_local_updates" metric 2026-03-18 11:18:37 +01:00
admin BUG/MINOR: admin: haproxy-reload rename -vv long option 2026-03-08 01:37:56 +01:00
dev DEV: gdb: add a new utility to extract libs from a core dump: libs-from-core 2026-03-18 15:30:39 +01:00
doc MINOR: debug: read all libs in memory when set-dumpable=libs 2026-03-18 15:30:39 +01:00
examples MINOR: mailers: warn if mailers are configured but not actually used 2025-06-27 16:41:18 +02:00
include MINOR: debug: read all libs in memory when set-dumpable=libs 2026-03-18 15:30:39 +01:00
reg-tests MINOR: jwt: Manage ec certificates in jwt_decrypt_cert 2026-03-10 14:58:47 +01:00
scripts SCRIPTS: git-show-backports: add a restart-from-last option 2026-03-09 15:36:05 +01:00
src BUG/MAJOR: h3: check body size with content-length on empty FIN 2026-03-19 10:38:46 +01:00
tests TESTS: quic: add unit-tests for QUIC TX part 2025-09-08 14:49:03 +02:00
.cirrus.yml CI: cirrus-ci: bump FreeBSD image to 14-3 2025-10-09 14:06:48 +02:00
.gitattributes MINOR: Configure the cpp userdiff driver for *.[ch] in .gitattributes 2021-02-22 18:17:57 +01:00
.gitignore MINOR: tevt/dev: Add term_events tool 2025-01-31 10:41:50 +01:00
.mailmap DOC: update Tim's address in .mailmap 2021-09-16 09:14:14 +02:00
.travis.yml MEDIUM: mworker: remove USE_SYSTEMD requirement for -Ws 2024-11-20 12:07:38 +01:00
BRANCHES DOC: clarify the experimental status for certain features 2025-10-17 18:41:13 +02:00
BSDmakefile BUILD: makefile: commit the tiny FreeBSD makefile stub 2023-05-24 17:17:36 +02:00
CHANGELOG [RELEASE] Released version 3.4-dev6 2026-03-05 15:55:28 +01:00
CONTRIBUTING CLEANUP: assorted typo fixes in the code and comments 2025-04-02 11:12:20 +02:00
INSTALL MINOR: version: mention that it's development again 2025-11-26 16:11:47 +01:00
LICENSE LICENSE: add licence exception for OpenSSL 2012-09-07 13:52:26 +02:00
MAINTAINERS MAJOR: spoe: Let the SPOE back into the game 2024-05-22 09:04:38 +02:00
Makefile DEV: gdb: add a new utility to extract libs from a core dump: libs-from-core 2026-03-18 15:30:39 +01:00
README.md DOC: remove openssl no-deprecated CI image 2026-02-19 10:39:23 +01:00
SUBVERS BUILD: use format tags in VERDATE and SUBVERS files 2013-12-10 11:22:49 +01:00
VERDATE [RELEASE] Released version 3.4-dev6 2026-03-05 15:55:28 +01:00
VERSION [RELEASE] Released version 3.4-dev6 2026-03-05 15:55:28 +01:00

HAProxy

alpine/musl AWS-LC Illumos NetBSD FreeBSD VTest

HAProxy logo

HAProxy is a free, very fast and reliable reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications.

Installation

The INSTALL file describes how to build HAProxy. A list of packages is also available on the wiki.

Getting help

The discourse and the mailing-list are available for questions or configuration assistance. You can also use the slack or IRC channel. Please don't use the issue tracker for these.

The issue tracker is only for bug reports or feature requests.

Documentation

The HAProxy documentation has been split into a number of different files for ease of use. It is available in text format as well as HTML. The wiki is also meant to replace the old architecture guide.

Please refer to the following files depending on what you're looking for:

  • INSTALL for instructions on how to build and install HAProxy
  • BRANCHES to understand the project's life cycle and what version to use
  • LICENSE for the project's license
  • CONTRIBUTING for the process to follow to submit contributions

The more detailed documentation is located into the doc/ directory:

License

HAProxy is licensed under GPL 2 or any later version, the headers under LGPL 2.1. See the LICENSE file for a more detailed explanation.