HAProxy known bugs for version v2.6.29 (maintenance branch 2.6) :  82 

This version (2.6.29) is a release belonging to maintenance branch 2.6 whose latest version is 2.6.32. 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
2026-07-292.6.32 ⇐ last
2026-07-032.6.31 
2026-06-262.6.30 
2026-05-112.6.29 ⇐ yours
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 

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

These fixes have already been queued for a more recent 2.6 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
82 0 1 32 49

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

Merge dateSubject - Severity (minor, medium, major, critical)
2026-07-29BUG/MEDIUM: sample: reject the deprecated protobuf group wire types
2026-07-29BUG/MEDIUM: peers: check the available room before encoding dict values
2026-07-29BUG/MINOR: slz: avoid undefined shifts when building the word byte by byte
2026-07-29BUG/MINOR: slz: fix the adler32 accumulators signedness on 32-bit
2026-07-29BUG/MINOR: slz: do not append a block to an already finished stream
2026-07-29BUG/MEDIUM: slz: bound the bits wasted by the 9-bit literals
2026-07-29BUG/MINOR: slz: use the exact switch cost for the last literals of a block
2026-07-29BUG/MINOR: slz: do not read past the end of the input around the match loop
2026-07-29BUG/MINOR: htx: Transfer HTX_FL_EOM flag on success in htx_append_msg()
2026-07-29BUG/MINOR: htx: Perform raw copy for messages of same size in htx_copy_msg()
2026-07-29BUG/MINOR: http-htx: check the strdup() of the "lf-string" http reply argument
2026-07-29BUG/MINOR: http-act: reject a negative capture id in the capture actions
2026-07-29BUG/MINOR: http-act: restore the response buffer state in the early-hint action
2026-07-29BUG/MINOR: http-act: fix a double free of the map reference on a parsing error
2026-07-29BUG/MINOR: http-act: fix a double free of the regex on a rule parsing error
2026-07-29BUG/MINOR: http-ana: fix a one-byte over-read in the client-side cookie parser
2026-07-29BUG/MINOR: h2: don't use a block pointer to roll back a partial HTX conversion
2026-07-29BUG/MINOR: http-htx: check the trash allocation in http_scheme_based_normalize()
2026-07-29BUG/MEDIUM: http-fetch: reject a negative capture id in capture.{req,res}.hdr
2026-07-29BUG/MEDIUM: http-fetch: don't parse a non-HTTP check buffer as an HTX message
2026-07-29BUG/MINOR: http-htx: fix the length moved when removing a header value
2026-07-22BUG/MEDIUM: sample: Adjust sample size capacity after pointer shift for ltrim()
2026-07-22BUG/MINOR: mux-h1: Don't delay send if message with c-l was fully sent
2026-07-22BUG/MEDIUM: protobuf: fix nested path bypass in field lookup
2026-07-22BUG/MEDIUM: protobuf: adjust sample size capacity after pointer shift
2026-07-22BUG/MEDIUM: ssl-gencert: Don't forget to free memory when done
2026-07-22BUG/MEDIUM: stats: Ensure that Origin is valid on POSTs
2026-07-22BUG/MEDIUM: stats: subject "stats admin" accesses to "stats scope" filtering
2026-07-22BUG/MINOR: http-conv: Make url-dec failed if no space for trailing null byte
2026-07-22BUG/MINOR: sample: Fix a possible underflow on be2hex for large chunk size
2026-07-02BUG/MINOR: http-htx: Don't by-pass HTX API when merging cookie values
2026-07-02BUG/MAJOR: htx: Don't swap buffers for empty HTX message with an error
2026-07-02BUG/MINOR: tools: fix invalid character detection in strl2ic()
2026-07-02BUG/MINOR: sample: set SMP_F_CONST on srv_name fetch
2026-06-26BUG/MEDIUM: mux-quic: Drain the given amount of data in qcs_http_reset_buf()
2026-06-26BUG/MEDIUM: mux-h2: Truly drain outgoing HTX data when the stream is closed
2026-06-26BUG/MEDIUM: mux-fcgi: Truly drain outgoing HTX data when the stream is closed
2026-06-26BUG/MINOR: server: fix add server with consistent hash balancing
2026-06-26BUG/MEDIUM: ssl: Don't free the early data buffer too early
2026-06-26BUG/MINOR: mux-h1: Properly resolve file path for 'h1-case-adjust-file'
2026-06-26BUG/MINOR: mux_h1: handle a possible strdup() failure
2026-06-26BUG/MEDIUM: http-ana: Don't ignore L7 retry errors
2026-06-26BUG/MEDIUM: check: Skip tcpcheck post-config for external checks
2026-06-26BUG/MEDIUM: mux-h1: Dup connection/upgrade value to parse it when making headers
2026-06-26BUG/MINOR: cache: Fix copy of value when parsing maxage
2026-06-26BUG/MINOR: qpack: fix huff_dec() error handling in qpack_decode_fs()
2026-06-26BUG/MINOR: qpack: fix sign bit mask in qpack_decode_fs_pfx()
2026-06-26BUG/MINOR: qpack: fix potential null-pointer dereference in qpack_dht_insert()
2026-06-26BUG/MINOR: qpack: Fix index calculation in debug functions
2026-06-26Revert "BUG/MEDIUM: dns: fix long loops in additional records parse on name failure"
2026-06-26BUG/MINOR: ssl-gencert: validate SNI characters to prevent SAN certificate injection
2026-06-26BUG/MINOR: mux-fcgi: Use relative offset to compute contig data in demux buf
2026-06-26BUG/MEDIUM: mux-fcgi: reject stream ID 0 for application records
2026-06-26BUG/MINOR: hlua: prevent Lua from passing CR/LF/NUL in HTTP headers
2026-06-26BUG/MEDIUM: auth: fix unconfigured password NULL deref
2026-06-26BUG/MINOR: addons/51d: NUL-terminate headers before passing them to Trie API
2026-06-26BUG/MINOR: ssl-hello: make use of the null-terminated servername
2026-06-26BUG/MINOR: payload: fix the handshake length bounds check smp_client_hello_parse()
2026-06-26BUG/MINOR: http-fetch: check against the whole token in get_http_auth()
2026-06-26BUG/MEDIUM: cache: always verify the primary hash in get_secondary_entry()
2026-06-26BUG/MINOR: sample: limit the be2hex converter's chunk size
2026-06-26BUG/MINOR: dict: fix refcount race on insert collision
2026-06-26BUG/MINOR: mux-h2: validate HEADERS frame length before reading stream dep
2026-06-26BUG/MINOR: resolvers: fix risk of appending garbage past the domain name
2026-06-26BUG/MINOR: resolvers: fix room for trailing zero in resolv_dn_label_to_str()
2026-06-26BUG/MEDIUM: log-forward: make sure the month is unsigned
2026-06-26BUG/MEDIUM: hlua: Fix integer underflow when receiving line from lua cosocket
2026-06-26BUG/MEDIUM: dict: hold lock while decrementing refcount in dict_entry_unref
2026-06-26BUG/MEDIUM: resolvers: Fix test on dn label size in resolv_dn_label_to_str()
2026-06-19BUG/MEDIUM: mux-fcgi: fix uint16_t overflow in drl += drp
2026-06-19BUG/MINOR: hpack-tbl: add missing NULL check after hpack_dht_defrag()
2026-05-21BUG/MEDIUM: server: Duplicate healthcheck's alpn inherited from default server
2026-05-21BUG/MINOR: h1: Don't mask websocket protocol if multiple protocols used
2026-05-21BUG/MEDIUM: h1: Skip all h2c values from Upgrade headers during parsing
2026-05-21BUG/MINOR: httpclient-cli: Destroy http-client context if failing to start it
2026-05-21BUG/MINOR: jwt: fix possible memory leak in convert_ecdsa_sig() error path
2026-05-21BUG/MINOR: resolvers: report the expression error in the do-resolve() action parser
2026-05-21BUG/MINOR: dns: fix dangling dgram pointer on dns_dgram_init() failure path
2026-05-21BUG/MEDIUM: dns: fix memory leak of sockaddr in dns_session_init() error path
2026-05-21BUG/MEDIUM: resolvers: fix name compression pointer validation in resolv_read_name()
2026-05-21BUG/MEDIUM: dns: fix long loops in additional records parse on name failure
2026-05-21BUG/MINOR: backend: correct parameter value validation in get_server_ph_post()
2026-05-21BUG/MEDIUM: dict: hold read lock while incrementing refcount in dict_insert

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