HAProxy known bugs for version v3.4.4 (maintenance branch 3.4) :  172 

This version (3.4.4) 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.

Quick links

Other versions in the same branch

This branch contains the following releases :

DateVersionComment
2026-10-143.4.7 ⇐ last
2026-09-283.4.6 
2026-09-243.4.5 
2026-08-273.4.4 ⇐ yours
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
172 0 9 67 96

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
2026-10-14BUG/MAJOR: h1-htx: report an error on a too long chunk-size line
2026-10-14BUG/MAJOR: mux-h2: properly handle short reads on PING frames
2026-10-13BUG/MINOR: cfgparse-global: only warn when "localpeer" is set together with -L
2026-10-12BUG/MEDIUM: mux-h1: only accept the H2 preface on the first request
2026-10-12BUG/MINOR: http-fetch: don't report pseudo-headers in TCP mode
2026-10-12BUG/MEDIUM: mux-h1: also release the embryonic stream when the error is empty
2026-10-12BUG/MEDIUM: mux-h2: fix a possible crash on rxbuf allocation failure
2026-10-12BUG/MEDIUM: mux-h2: report a dead rhttp connection in h2_wake()
2026-10-12BUG/MEDIUM: mux-h1: don't pass an upgraded connection to traces in h1s_destroy()
2026-10-12BUG/MEDIUM: mux-fcgi: don't return a freed tasklet from fcgi_deferred_shut()
2026-10-12BUG/MEDIUM: mux-h2: don't return a freed tasklet from h2_deferred_shut()
2026-10-12BUG/MINOR: hlua: assume proxy_find_by_id() may return NULL on previously existing server
2026-10-12BUG/MINOR: spoe: Fix the message list splice with an empty list
2026-10-12BUG/MEDIUM: log: do not ignore the peer's shutdown in the syslog applet
2026-10-12BUG/MEDIUM: cli: fix the last command detection on a full command line
2026-10-12BUG/MINOR: cfgparse-listen: complete the list of options for the suggestions
2026-10-12BUG/MINOR: proxy: also look for the closest option among cfg_opts3
2026-10-12BUG/MINOR: cfgparse-listen: properly reject extra args in a backend section
2026-10-12BUG/MINOR: cfgparse-listen: fix quoting of the condition conflict warning
2026-10-12BUG/MINOR: cfgparse-listen: fix the argument checked by "email-alert"
2026-10-12BUG/MINOR: cfgparse-listen: release the previous description of the proxy
2026-10-12BUG/MINOR: cfgparse-global: add missing calloc() check for the global description
2026-10-12BUG/MINOR: cfgparse-global: add missing gotos to error label in max-spread-checks
2026-10-12BUG/MAJOR: cfgparse: properly check userlist section when scanning keywords
2026-10-12BUG/MINOR: ssl: Fix potential NULL-deref in "dump ssl cert" with AWS-LC
2026-10-12BUG/MINOR: h3: reject RS/SS for QPACK uni streams
2026-10-12BUG/MINOR: h3: close connection on GOAWAY frame too long
2026-10-12BUG/MINOR: h3: reject frames with truncated header
2026-10-12BUG/MINOR: mux_quic: extend FINAL_SIZE_ERROR detection on stream
2026-10-12BUG/MINOR: ssl: use standard names for X25519 and X448 groups
2026-10-12BUG/MEDIUM: listener: Consider maxconn before waking listeners
2026-10-12BUG/MEDIUM: ssl: crt-list curves ignored with AWS-LC
2026-10-12BUG/MEDIUM: ssl: crt-list ciphers ignored with AWS-LC
2026-10-12BUG/MINOR: ssl: fix trace crash on BE conn release in io cb
2026-10-12BUG/MINOR: ssl: fix trace crash on FE conn release in io cb
2026-10-12BUG/MINOR: hq-interop: prevent double EOM on request with standalone FIN
2026-10-12BUG/MINOR: log: fix erroneous error message in log-steps parser
2026-10-12BUG/MINOR: cli: update wait help usage
2026-10-12BUG/MINOR: server: fix "del server" description
2026-10-12BUG/MINOR: proxy: add PR_CAP_LB for dynamically added backend
2026-10-12BUG/MINOR: sample: return the decoded JWT part when no path is given
2026-10-12BUG/MEDIUM: tcpcheck: do not run a regex on an unallocated buffer
2026-10-12BUG/MINOR: http-fetch: do not count Set-Cookie attributes as cookies
2026-10-12BUG/MINOR: payload: always report a boolean from req.ssl_ec_ext
2026-10-12BUG/MINOR: stick-table: do not count the lookup itself in table_trackers()
2026-10-12BUG/MINOR: http-ana: return a 502 when checkcache blocks a response
2026-10-12BUG/MINOR: sample: make quic_enabled() always succeed
2026-10-12BUG/MINOR: sample: zero-pad the fractional part emitted by http_date()
2026-10-12BUG/MINOR: sample: apply the ms_/us_ time offsets in the input unit
2026-10-12BUG/MINOR: http: do not consume the delimiter of a truncated q-factor
2026-10-12BUG/MINOR: jwe: Avoid buffer overflow in fake cek (RSA1.5)
2026-10-12BUG/MINOR: jwe: Buffer overflow when filling fake cek in case of RSA1.5
2026-10-12BUG/MEDIUM: pattern: don't dereference static_pattern's data when not filling it
2026-10-12BUG/MEDIUM: stick-table: restrict key sizes to what fits in a buffer
2026-10-12BUG/MINOR: flt-http-comp: Rely on htx_set_eom() to restore EOM flag
2026-10-12BUG/MEDIUM: flt-http-comp: Block HTX_FL_EOM flag till the end of compression
2026-09-28BUG/MEDIUM: server: skip log backend addr checks for internal proxies
2026-09-28BUG/MEDIUM: sink: reconnect attempt not working after session lasted more than ~25 days
2026-09-28BUG/MAJOR: mux_quic: fix potential crash on RESET_STREAM receive
2026-09-24BUG/MINOR: mux-h2: Reject trailers received on a tunneled stream
2026-09-24BUG/MEDIUM: log: encode the whole non-printable range in the +json output
2026-09-24BUG/MEDIUM: mux_quic: activate timeout on FE init
2026-09-24BUG/MAJOR: mux_quic: fix leak on RESET_STREAM reception
2026-09-23BUG/MINOR: http-ana: restore the transaction status after early hints
2026-09-23BUG/MINOR: tcpcheck: refresh the start-line after updating the authority
2026-09-23BUG/MINOR: mux-h1: only mark C-L and T-E as sent once the header is emitted
2026-09-23BUG/MINOR: http-fetch: fix the space check of http_auth_bearer()
2026-09-23BUG/MINOR: http-fetch: http_auth_bearer() must not match a missing header
2026-09-23BUG/MINOR: http-ana: count response body failures only once in http_fail_cnt
2026-09-23BUG/MEDIUM: tcp-rules: ignore "capture len" rules evaluated from a backend
2026-09-23BUG/MEDIUM: http-act: ignore "capture len" rules evaluated from a backend
2026-09-23BUG/MEDIUM: http-htx: don't build the new authority in a rotating trash chunk
2026-09-23BUG/MEDIUM: log: reserve the trailing 0 in CBOR int and bool encoders
2026-09-23BUG/MINOR: mux-h2: Don't expect more HTX data on 1xx interim responses
2026-09-23BUG/MINOR: http-client: Convert server timeout ticks when setting it
2026-09-21BUG/MINOR: ssl: Fix possible null deref on the SSL context in ssl_sock_to_buf()
2026-09-21BUG/MINOR: hlua: release private Lua rule data on teardown
2026-09-21BUG/MAJOR: htx: Check the header/trailer length limits when one is updated
2026-09-21BUG/MINOR: tools: Don't try to anonymize a NULL string
2026-09-21BUG/MEDIUM: htx: Fix the position returned by htx_defrag()
2026-09-21BUG/MEDIUM: http-client/cli: Notify the http-client when the response is consumed
2026-09-21BUG/MEDIUM: acme: Set HTTPCLIENT_O_RES_ACCUM option on the http-client
2026-09-21BUG/MEDIUM: ssl/ocsp: Set HTTPCLIENT_O_RES_ACCUM option on the http-client
2026-09-21BUG/MEDIUM: http-client: Don't use the httpclient context if it was released
2026-09-21BUG/MEDIUM: task: Do not destroy a task that is not ours in task_destroy
2026-09-16BUG/MINOR: proxy: pass PR_FL_DEF_EXPLICIT_MODE through cascaded defaults
2026-09-16BUG/MEDIUM: tcp-rules: Don't restart tcp-request content evaluation on yield
2026-09-16BUG/MEDIUM: htx: Reserve a block descriptor for zero-sized blocks
2026-09-16BUG/MEDIUM: ssl: don't set a 0 timeout on an expired TLS session
2026-09-16BUG/MINOR: sample: reject a \0 byte in url_dec, json_query and jwt_*_query
2026-09-16BUG/MINOR: ssl: Fix leak of ca_list in cafile_entry
2026-09-16BUG/MINOR: cli: Reject payload with no command
2026-09-16BUG/MEDIUM: cli: Don't read a command or payload line into a full buffer
2026-09-16BUG/MEDIUM: cli: Don't parse next command if input buffer is empty
2026-09-16BUG/MEDIUM: http_act: fix normalize-uri normalizer selection with a condition
2026-09-16BUG/MEDIUM: map: do not overwrite the fetch context in pat_match_regm()
2026-09-16BUG/MINOR: ssl: don't pass the address of a size_t as an int* to OpenSSL
2026-09-16BUG/MEDIUM: http-ana: apply tunnel timeout with data filters
2026-09-16BUG/MINOR: h3: only increment frame type counter on new header
2026-09-16BUG/MINOR: h3: handle unknown frame type on request stream as specified
2026-09-16BUG/MINOR: h3: handle empty HEADERS frame as specified
2026-09-16BUG/MEDIUM: h3: do not block FIN on empty DATA frame
2026-09-16BUG/MINOR: h3: reject truncated frames with mandatory payload
2026-09-16BUG/MINOR: stream/debug: harden the stream dump function regarding signals
2026-09-16BUG/MEDIUM: htx: Don't reset flags when source must be preserved during transfer
2026-09-16BUG/MINOR: hlua: Always return nil if there is no data to dup for HTTP messages
2026-09-16BUG/MINOR: mux-h1: Return an error on trailers if last chunk is unfinished
2026-09-16BUG/MEDIUM: hlua: Never release a cosocket applet from the GC
2026-09-16BUG/MINOR: quic: leak of the NEW_TOKEN frame on token generation failure
2026-09-16BUG/MAJOR: h3: reject H3 truncated frames
2026-09-16BUG/MEDIUM: mux-h2: Make sure we remove H2_SF_NOTIFIED on subscribe
2026-09-16BUG/MINOR: quic: delete the wrong CIDs when post-handshake frames fail
2026-09-16BUG/MINOR: qpack: accept a Required Insert Count which cannot be reached
2026-09-16BUG/MINOR: qpack: encoder and decoder stream data is never consumed
2026-09-16BUG/MINOR: resolvers: classify empty truncated responses
2026-09-16BUG/MEDIUM: filters: check the filter name before comparing it
2026-09-16BUG/MINOR: quic: late packets of the first key phase are dropped
2026-09-16BUG/MEDIUM: quic: crash on key update phase change after a failed one
2026-09-16BUG/MINOR: payload: bound ClientHello extension lists by the extension length
2026-09-16BUG/MINOR: payload: fix the cipher_len bound check in smp_client_hello_parse()
2026-09-16BUG/MEDIUM: mux-spop: Properly handle parsing of split HELLO/DISCONNECT frames
2026-09-16BUG/MINOR: cache: Seed cache primary hash
2026-09-16BUG/MINOR: cache: Manage collisions on primary key

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