HAProxy known bugs for maintenance branch 2.6 :  0 

This is maintenance branch 2.6 whose latest version is 2.6.29. If your version is not the last one in the maintenance branch, you are missing fixes for known bugs, and by not updating you are needlessly taking the responsibility for the risk of unexpected service outages and exposing your web site to possible security issues.

The HAProxy development team takes a great care of maintaining stable versions so that all users can apply bug fixes without having to take the risk of upgrading to a new branch. In turn users are expected to apply the fixes when the development team estimates that they were worth being backported to stable branches. In short, if you are running any 2.6 version other than 2.6.29, you're running with known bugs.

Quick links

Versions available in this branch

This branch contains the following releases :

DateVersionComment
2026-05-112.6.29 ⇐ last
2026-05-062.6.28 
2026-04-302.6.27 
2026-04-232.6.26 
2026-03-202.6.25 
2026-03-092.6.24 
2025-10-032.6.23 
2025-04-222.6.22 
2025-01-292.6.21 
2024-11-082.6.20 
2024-09-192.6.19 
2024-06-182.6.18 
2024-04-052.6.17 
2023-12-132.6.16 
2023-08-092.6.15 
2023-06-092.6.14 
2023-05-022.6.13 
2023-03-282.6.12 
2023-03-172.6.11 
2023-03-102.6.10 
2023-02-142.6.9 
2023-01-242.6.8 
2022-12-022.6.7 
2022-09-222.6.6 
2022-09-032.6.5 
2022-08-222.6.4 
2022-08-192.6.3 
2022-07-222.6.2 
2022-06-212.6.1 
2022-05-312.6.0 

Fixes for known bugs pending in this branch since the last release (2.6.29)

These fixes have already been queued for the next 2.6 release but no version was released with them yet. Note that fixes are backported several at a time from the development branch to maintenance branches, and the absence of a fix here doesn't mean none will be issued soon.

Bugs are almost always tagged with a severity (some people forget the severity tag when the bug is minor). The following severities are used :

Total known bugs in the latest version of this branch by category :

TotalCRITICALMAJORMEDIUMMINOR
0 0 0 0 0

Click on the subjects below to get the full description of the bug :

Merge dateSubject - Severity (minor, medium, major, critical)

Known bugs fixed in the development branch after the last commit in this branch

It is important to understand that not all of these commits are necessarily relevant to this version, but clicking on them will show the bug description. All fixes are made first in the development branch and then backported to the maintenance branches. This ensures no fix is lost when upgrading. If a fix was marked for backporting to this branch and is not there yet, it's likely that it is still missing. Do not hesitate to ask on the haproxy mailing list if you feel like a fix has been skipped.

DateSubject
2026-05-20BUG/MEDIUM: htx: Alloc a chunk of right size in htx_replace_blk_value()
2026-05-20BUG/MEDIUM: applet: Fix transfer of HTX data to the applet
2026-05-20BUG/MINOR: htx: Fix value of HTX_XFER_HDRS_ONLY flag
2026-05-20BUG/MINOR: mux_quic: do not exceed stream.max-concurrent on backend side
2026-05-20BUG/MEDIUM: servers: Don't forget to set srv_hash when needed
2026-05-20BUG/MINOR: prevent conn leak in case of xprt_qmux init failure
2026-05-20BUG/MEDIUM: servers: Store the connection hash with the parameter cache
2026-05-19BUG/MINOR: backend: fix balance hash calculation when using hash-type none
2026-05-19BUG/MINOR: server: accept server IDs above 2^31 and clarify error message
2026-05-19BUG/MINOR: httpclient-cli: fix uninit variable in error label
2026-05-19BUG/MINOR: h1: Don't mask websocket protocol if multiple protocols used
2026-05-19BUG/MEDIUM: h1: Skip all h2c values from Upgrade headers during parsing
2026-05-19BUG/MINOR: httpclient-cli: Destroy http-client context if failing to start it
2026-05-19BUG/MINOR: server: Properly handle init-state value during haproxy startup
2026-05-19BUG/MINOR: jws: Add missing return value check (EVP_PKEY_get_bn_param)
2026-05-19BUG/MINOR: jws: fix OpenSSL 3.0 version check from > to >=
2026-05-19BUG/MEDIUM: limits: properly account for global.maxpipes in compute_ideal_maxconn()
2026-05-18BUG/MINOR: jwt: fix possible memory leak in convert_ecdsa_sig() error path
2026-05-18BUG/MINOR: check: properly report errno in chk_report_conn_err()
2026-05-18BUG/MINOR: sock: store the connection error status
2026-05-16BUG/MINOR: session/trace: use distinct flags for SESS_EV_END and _ERR
2026-05-15BUG/MINOR: resolvers: fix missing task_idle destruction in resolvers_destroy()
2026-05-15BUG/MINOR: resolvers: fix leaked fields on cfg_parse_resolvers() error paths
2026-05-15BUG/MINOR: resolvers: fix leaked dgram and dns_ring struct in parse_resolve_conf()
2026-05-15BUG/MINOR: resolvers: report the expression error in the do-resolve() action parser
2026-05-15BUG/MINOR: proxy: use proxy_drop() in parse_new_proxy() error path
2026-05-15BUG/MINOR: dns: fix dangling dgram pointer on dns_dgram_init() failure path
2026-05-15BUG/MINOR: resolvers: fix dangling list pointer in resolvers_new() error paths
2026-05-15BUG/MEDIUM: server/cli: unlock server lock on failure in cli_parse_set_server
2026-05-15BUG/MINOR: servers: use proper source of pool_conn_name in srv_settings_cpy()
2026-05-15BUG/MINOR: server: better handling of OOM in srv_set_fqdn()
2026-05-15BUG/MEDIUM: dns: fix memory leak of sockaddr in dns_session_init() error path
2026-05-15BUG/MEDIUM: resolvers: fix name compression pointer validation in resolv_read_name()
2026-05-15BUG/MEDIUM: dns: fix long loops in additional records parse on name failure
2026-05-15BUG/MINOR: config/dns: properly fail on duplicate nameserver name detection
2026-05-15BUG/MINOR: backend: correct parameter value validation in get_server_ph_post()
2026-05-13BUG/MINOR: xprt_qstrm: fix conflicting prototype
2026-05-13BUG/MEDIUM: http-client: Only consume input buffer when hc one is empty
2026-05-13BUG/MEDIUM: dict: hold read lock while incrementing refcount in dict_insert

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