HAProxy known bugs for version v3.4.7 (maintenance branch 3.4) :  49 

This version (3.4.7) is a release belonging to maintenance branch 3.4 whose latest version is 3.4.7. 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.

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Other versions in the same branch

This branch contains the following releases :

DateVersionComment
2026-10-143.4.7 ⇐ yours ⇐ last
2026-09-283.4.6 
2026-09-243.4.5 
2026-08-273.4.4 
2026-07-293.4.3 
2026-07-033.4.2 
2026-06-253.4.1 
2026-06-033.4.0 

Known bugs affecting this version, and already fixed in the maintenance branch

These fixes have already been queued for a more recent 3.4 version. Some of them might have already been released in a more recent version than yours, and other ones might still be pending in the maintenance branch for a future release. The list may be empty if you're already on the latest version and no new fix was backported.

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 this version by category :

TotalCRITICALMAJORMEDIUMMINOR
49 0 2 22 25

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

Merge dateSubject - Severity (minor, medium, major, critical)
2026-10-20Revert "BUG/MAJOR: mux-quic: do not crash on connection error after glitch threshold"
2026-10-20BUG/MINOR: h3: fix BUG_ON() crash with glitch on htx_set_eom() failure
2026-10-20BUG/MINOR: h3: fix risk of BUG_ON() crash with glitch on unknown frame
2026-10-20BUG/MEDIUM: h3: fix BUG_ON() crash with glitch after QPACK dec err
2026-10-20BUG/MEDIUM: h3: fix BUG_ON() crash with glitch on GOAWAY parsing
2026-10-20BUG/MEDIUM: h3: fix BUG_ON() crash with glitch on SETTINGS parsing
2026-10-20BUG/MINOR: sample: Fix wrong 'base64urldec' return value check in 'jwt_member_query'
2026-10-20BUG/MEDIUM: bwlim: never burst more than the pending data in input
2026-10-20BUG/MEDIUM: h3: split absolute URIs like the HTTP analysers do on output
2026-10-20BUG/MAJOR: mux-h2: split absolute URIs like the HTTP analysers do on output
2026-10-20BUG/MAJOR: mux-quic: do not crash on connection error after glitch threshold
2026-10-20BUG/MEDIUM: resolvers: reject too long labels when encoding a name
2026-10-20BUG/MINOR: mux-h1: Don't subscribe for receives once read0 or error received
2026-10-20BUG/MEDIUM: mux-h1: don't spread-close idle conns with idle-close-on-response
2026-10-20BUG/MINOR: mux-h1: don't forward request trailers named like server name header
2026-10-20BUG/MINOR: mux-h1: search the websocket key in the right message
2026-10-20BUG/MINOR: mux-h1: only rely on the client's method for bodyless responses
2026-10-20BUG/MINOR: mux-h1: convert the argument of h1-case-adjust to lower case
2026-10-20BUG/MEDIUM: mux-h1: don't send chunked responses to HTTP/1.0 clients
2026-10-20BUG/MINOR: h1: forget a previous pass' results when parsing headers only
2026-10-20BUG/MEDIUM: mux-h1: don't lose error responses once a content-length was parsed
2026-10-20BUG/MINOR: mux-h1: report payload parsing glitches to the session
2026-10-20BUG/MEDIUM: mux-h1: don't swap buffers when transferring data with a reserved offset
2026-10-20BUG/MINOR: mux-h1: don't report a 408 error on timeout of a closed connection
2026-10-20BUG/MINOR: mux-h1: don't keep fast-forwarding disabled for the next streams
2026-10-20BUG/MINOR: mux-h1: reset the content-length/chunking state after a 1xx response
2026-10-20BUG/MEDIUM: mux-h1: don't stall when draining more than a buffer of data
2026-10-20BUG/MEDIUM: mux-h1: don't lose the end of the previous chunk in h1_make_chunk()
2026-10-20BUG/MINOR: mux-h1: don't dereference a NULL opposite sedesc in h1_fastfwd()
2026-10-20BUG/MINOR: mux-h1: fix the open streams counter on stream creation failure
2026-10-20BUG/MINOR: mux-h1: only reset the session's timing info on the frontend side
2026-10-20BUG/MINOR: h1: don't use uninitialized start line pointers when restarting
2026-10-20BUG/MEDIUM: mux-h1: don't truncate responses on soft-stop
2026-10-20BUG/MEDIUM: mux-h1: don't truncate the response when closing after draining
2026-10-20BUG/MEDIUM: h1-htx: don't stall on messages ending exactly at the buffer's end
2026-10-20BUG/MEDIUM: h1: don't rewrite the Upgrade header when not cleaning headers
2026-10-20BUG/MINOR: h1: keep accepting unsafe violations after a parser reset
2026-10-20BUG/MEDIUM: h1: make the Connection/Upgrade headers cleanup idempotent
2026-10-20BUG/MEDIUM: mux-h1: Don't close the connection on a payload parsing error
2026-10-20BUG/MEDIUM: cli: Fix parsing of big payloads with dynamically allocated buffer
2026-10-20BUG/MINOR: quic: valid NEW_TOKEN connections are counted as half-open
2026-10-20BUG/MEDIUM: peers: keep the earliest sync task deadline
2026-10-20BUG/MINOR: mux_quic: do not crash on SE_SHR_DRAIN shut
2026-10-20BUG/MINOR: check: do not inspect errno if conn FDLESS
2026-10-20BUG/MINOR: mux_quic: prevent RS/SS on unistream with hq-interop
2026-10-20BUG/MINOR: quic: handle EINTR on emission of packets without connection
2026-10-20BUG/MINOR: quic: use datagram destination as source for version negotiation
2026-10-20BUG/MINOR: quic: use datagram destination as source for stateless reset
2026-10-20BUG/MEDIUM: quic: use datagram destination as source for Retry
2026-10-20BUG/MEDIUM: stats-file: shm-stats-file be counters not working anymore

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