https://docs.rspamd.com/assets/js/8f11d9f7.973dbae2.js

1"use strict";(self.webpackChunkrspamd_docs=self.webpackChunkrspamd_docs||[]).push([[6551],{49404:e=>{e.exports=JSON.parse('{"version":"4.1.1","date":"2026-06-19","type":"patch","title":"Patch Release with checkv3 Content Negotiation, Neural Extensibility, CSS Hidden-Text Detection, and 4.1.0 Regression Fixes","sections":[{"title":"Added","items":["**/checkv3 content negotiation**: The `/checkv3` reply now honours the client\'s `Accept` and `Accept-Encoding` headers at the single `reply_v3` chokepoint shared by the scan worker, `rspamd_proxy`, and the controller. `application/json` / `application/msgpack` yield a plain v2-style single-body reply, `message/rfc822` a `multipart/mixed` envelope, and `multipart/form-data` (also the default for an absent or wildcard `Accept`) a true form-data envelope; an `Accept` listing only unsupported types returns `406 Not Acceptable`. Compression is negotiated separately \u2014 `zstd` when offered, identity otherwise \u2014 and `Vary: Accept, Accept-Encoding` is always advertised. `rspamc` now requests `multipart/form-data` and accepts any `multipart/` subtype ([#6083](https://github.com/rspamd/rspamd/pull/6083))","**CSS hidden-text detection**: The invisible-text detector learns several more CSS tricks used to dilute visible spam with hidden ham text \u2014 off-screen positioning (`position:absolute|fixed` with a large negative `left`/`top`), image-replacement `text-indent`, `clip` / `clip-path` collapsing the element to zero area (`rect(0,0,0,0)`, `inset(100%)`, `circle(0)`), `visibility:collapse`, and tiny font sizes (\u2264 3px). These are now modelled as a hidden display so the effect correctly propagates to descendants, replacing a fragile substring heuristic that only bumped a feature counter and never actually hid the text","**Zip-bomb extraction limits**: `lua_archive` (`unpack` / `unzip` / `untar`) gains an optional `opts` table that caps extraction while reading, so a tiny hostile archive can no longer expand to gigabytes and OOM the worker: `max_output` (total uncompressed bytes), `max_file_size` (per-member cap, truncated at the cap), `max_files` (member count), and `max_ratio` (per-member uncompressed/compressed ratio). The ratio uses real compressed bytes consumed, checked per chunk above a 64 KiB floor, so a bomb is stopped early even with no size cap set. All limits are opt-in (0/absent = unlimited), preserving the previous behaviour, and a second boolean return flags truncation so a capped extraction is never mistaken for a complete one","**Byte-distribution statistics for rspamd_text**: New methods on the `rspamd_text` class expose ENT-style byte statistics for content analysis \u2014 `entropy()`, `byte_mean()`, `byte_deviation(mean)`, `serial_correlation()`, and `monte_carlo_pi()`. Each takes an optional 1-based `(start, len)` range (consistent with the rest of the slicing API), runs O(n) over a single shared histogram pass, and produces deterministic, bit-reproducible results ([#6106](https://github.com/rspamd/rspamd/pull/6106))","**zlib/YARA-compatible CRC-32**: Standard CRC-32 (poly `0xEDB88320`) is now available as `rspamd_text:crc32([start[, len]])`, `rspamd_util.crc32(input[, start, len])`, and a streaming `rspamd_cryptobox_hash.create_specific(\\"crc32\\")`, bit-exact with `zlib crc32()` and YARA\'s `hash.crc32` (e.g. `\\"123456789\\"` \u2192 `0xCBF43926`). The text/util forms return a Lua integer over a zero-copy 1-based slice with no buffer copy","**Explicit multipattern SOM flag**: `RSPAMD_MULTIPATTERN_SOM` (`rspamd_trie.flags.som`) explicitly requests start-of-match offsets, overriding the incompatible single-match flag. The offset convention is now documented \u2014 1-based pattern id, 0-based byte offsets, start inclusive and end exclusive (so `end - start` is the match length) \u2014 and the regex fallback used when hyperscan is unavailable now reports the true start/end from the PCRE search instead of a bogus `end - strlen(pattern)` for variable-length matches ([#6105](https://github.com/rspamd/rspamd/pull/6105))","**Pluggable neural registries**: The neural plugin becomes an extension point so third-party (including closed-source) modules can add feature providers and network topologies without patching the core. `register_architecture(name, builder)` / `get_architecture(name)` join the existing `register_provider`; the built-in `symbol`, `embedding`, and `conv1d` architectures are now registered through it, `create_ann()` dispatches on `rule.architecture` and falls back to the historical auto-selection when it is unset (so existing configs are unaffected), and an unknown architecture now fails loudly with a hint that the providing module may not be loaded","**fasttext_embed sequence output**: The `fasttext_embed` provider gains `output_mode = \\"sequence\\"`, emitting the first `max_words` word vectors flattened word-major and zero-padded to `max_words * channels`, so custom architectures can learn their own pooling instead of receiving a pre-pooled vector. An optional `word_selection = \\"sif\\"` fills the sequence with the most distinctive (highest SIF weight) words from anywhere in the message rather than the leading ones; the default stays `prefix`","**Multi-head attention pooling**: A new `attn_pool` KANN operator performs multi-head dot-product attention pooling over a zero-padded sequence of word vectors with learned query vectors, masking all-zero padding positions out of the softmax. Exposed as `rspamd_kann.layer.attn_pool(node, n_words[, n_heads])`, it converges on a word-order-invariant needle-in-haystack task that a flat dense net cannot solve, and the operator is appended to preserve model serialization compatibility","**KANN slice and concat transforms**: `rspamd_kann.transform.slice(node, axis, start, end)` (0-based, end exclusive) and `rspamd_kann.transform.concat(axis, node1, node2, ...)` expose the already-serialized `k

1ad_slice` / `kad_concat_array` graph operators to Lua, making split/bypass/merge topologies \u2014 e.g. routing parts of a fused input vector through different sub-networks for attention pooling with late fusion \u2014 buildable from Lua"]},{"title":"Fixed","items":["**DNS resolver startup crash (4.1.0 regression)**: A nameserver that failed to resolve at config time was turned into a zero-address pending-resolve upstream and then dereferenced as NULL in `rspamd_dns_server_init`, crashing the worker with SIGSEGV at startup. Resolver nameservers are consumed synchronously and can never be promoted asynchronously, so they are no longer deferred, with a NULL guard added as defense in depth ([#6096](https://github.com/rspamd/rspamd/issues/6096))","**Milter QUARANTINE with custom reply (3.10.0 regression)**: The QUARANTINE command was emitted only inside the branch that synthesises a default quarantine reason, so a caller-supplied SMTP message (e.g. `task:set_pre_result(\'quarantine\', \'reason\')`) suppressed the command entirely and the message was accepted instead of quarantined. The supplied message now becomes the quarantine reason, matching the reject and tempfail branches; this affects both `METRIC_ACTION_QUARANTINE` and reject converted via `quarantine_on_reject` ([#6088](https://github.com/rspamd/rspamd/issues/6088))","**Coroutine thread-pool safety**: Async Lua libraries (DNS, Redis, TCP, HTTP, util) capture the running coroutine at a yield point and resume it later from a C completion callback, with nothing previously guaranteeing the resumed entry was still the captured one. Each pooled thread now carries an explicit lifecycle and generation counter, and the entries are refcounted, so a double-fired event, a completion racing task teardown, or an entry recycled into another task either resumes the correct live coroutine or becomes a logged no-op \u2014 instead of dereferencing freed memory ([#6104](https://github.com/rspamd/rspamd/pull/6104))","**lua_worker subprocess deadlock**: A function run via `worker:spawn_process` that returned `nil` (or any non-string value) logged an error but wrote nothing to the result pipe, so the parent waited forever for a reply while the child blocked on the post-reply ack \u2014 deadlocking both processes and anything serialised behind them, notably the neural training lock. Invalid return values are now reported to the parent as a regular error reply, so `on_complete` fires and the caller can recover","**Neural training on dense embeddings**: Training on dense provider features (`fasttext_embed`, `text_hash`) with the historical `learning_rate = 0.01` could drive the net into tanh saturation and silently save a degenerate single-class model that classified every message the same way until the next retrain \u2014 roughly one weight-init in three on a real corpus. Dense-feature rules now use the funnel (embedding) architecture, whose layernorm fixes the conditioning; the learning-rate default is resolved by input type (0.001 for dense embeddings, 0.01 for symbol vectors, an explicit config value still wins); and a quality gate rejects a constant/single-class model so training retries on the next cycle with a different init","**Stranded trained ANNs**: A trained ANN could become unreachable to workers \u2014 `NEURAL_SPAM` / `NEURAL_HAM` stopped firing while the controller logged a version mismatch forever \u2014 because a stale, empty, high-version profile entry shadowed the live lower-version blob and, with no TTL, never expired. New versions are now seeded monotonically from the profile actually trained from, selection falls back to the next compatible profile with a live blob (with a throttled warning) when the chosen one is missing, and profile/blob entries get a TTL refreshed each cycle so an actively used ANN never expires out from under its entry ([#6089](https://github.com/rspamd/rspamd/pull/6089))","**mx_check loopback classification**: A domain whose MX resolves only to loopback is hosted on the scanning host itself (typically the host\'s own FQDN mapped to `127.0.0.1` in `/etc/hosts`), but it scored `MX_BOGON_ONLY` (+8.0) \u2014 the strongest \\"not spam infrastru

1cture\\" signal treated as the strongest spam signal, penalising fully DMARC-aligned self-hosted mail. `127.0.0.0/8` and `::1/128` move from the bogon set to the local set, so such mail now emits `MX_LOCAL_ONLY` (3.0) ([#6101](https://github.com/rspamd/rspamd/issues/6101))","**Monitored random DNS prefixes**: `random_monitored` RBL checks built random labels from an alphabet including `-` and `_`, producing names like `_Q8...0-` or `-7d0...` that are not valid DNS labels (RFC 952/1123) and that authoritative DNSBL servers such as spfbl.net reject with SERVFAIL. The alphabet is restricted to alphanumerics, which always forms a valid label regardless of position while keeping ample entropy ([#6103](https://github.com/rspamd/rspamd/issues/6103))","**v3 multipart boundary case**: RFC 2046 boundaries are case-sensitive, but the v3 HTTP multipart callers used the boundary lowercased for MIME-client quirks, so requests with uppercase boundary characters failed to parse. The case-preserving `orig_boundary` is now used in `protocol.c`, `rspamd_proxy.c`, and `rspamdclient.c`","**/checkv3 on the controller**: The controller\'s HTTP path router never registered `/checkv3`, so a plain `rspamc --protocol-v3` \u2014 which defaults to the controller port 11334 on localhost \u2014 returned 404. The endpoint is now registered and routed to the existing scan handler, branching on `CMD_CHECK_V3` in both directions to mirror the proxy, with an auth posture matching `/check` and `/checkv2` ([#6083](https://github.com/rspamd/rspamd/pull/6083))","**Symcache timeout inflation**: A `saved_priority` initialised to `-1` split the first item of each pre/postfilter/idempotent phase off from its priority group and counted it individually, inflating the computed maximum symbols-cache timeout. It is now seeded from the first item\'s priority so items at the same priority group correctly ([#6094](https://github.com/rspamd/rspamd/pull/6094), [#6092](https://github.com/rspamd/rspamd/issues/6092))","**Query-embedded URLs with \'=\'**: A bare embedded URL is its own query parameter and can itself contain `=` (e.g. base64 padding in the path), but the query-embedded scan treated everything before the first `=` as a parameter key and discarded such URLs. The prefix is now treated as a key only when it has no URL structure characters (`:` or `/`); otherwise the whole parameter is scanned","**URLs with multiple \'@\' and backslashes**: URLs containing several `@` signs and backslashes were multiplied into many spurious URLs. Long legitimate conversations can accumulate such links, so the spurious expansion could drop mail and, with autotrain enabled, train the system badly; those URLs are no longer multiplied ([#6065](https://github.com/rspamd/rspamd/pull/6065))","**More CSS hiding via overflow/opacity/max-***: Phishing that dilutes visible content with hidden ham text using `max-width:0;max-height:0;overflow:hidden`, `opacity:0`, or `height:0` was missed \u2014 `max-*` and `overflow` were unparsed, `opacity` was parsed but discarded, and a copy-paste bug applied `height:0` to the block width. These properties are now parsed, a zero-dimension-with-`overflow:hidden`, low-opacity, or hidden-ancestor block is treated as invisible and propagated to descendants, and a child display value can no longer resurrect content hidden by an ancestor","**OpenSSL 4.0 build**: OpenSSL 4.0 made `ASN1_STRING` (and thus `ASN1_OCTET_STRING`) opaque, so direct access to its length/data fields no longer compiled; `ASN1_STRING_length()` / `ASN1_STRING_get0_data()` (available since OpenSSL 1.1.0 and LibreSSL 2.7) are used instead, and the legacy OpenSSL init calls are moved under the pre-1.1.0 guard to fix no-deprecated builds ([#6087](https://github.com/rspamd/rspamd/issues/6087))","**doctest 2.5.0 build**: `mime_string`\'s iterator is intrinsically const, so it is marked as such and the `const_iterator` reference is dropped, fixing a compile error where doctest 2.5.0 receives a const reference and cannot use a mutable iterator ([#6072](https://github.com/rspamd/rspamd/pull/6072))","**Bundled simdutf headers**: The bundled simdutf headers are now prioritised over system ones to avoid version skew ([#6082](https://github.com/rspamd/rspamd/pull/6082))"]}],"summary":"This patch release fixes a critical 4.1.0 regression that crashed workers at startup when a DNS nameserver failed to resolve, restores milter QUARANTINE handling broken since 3.10.0, and hardens the async Lua coroutine pool against use-after-free on completion races. It also adds `/checkv3` content negotiation via `Accept`/`Accept-Encoding`, opt-in archive extraction limits against zip bombs, broader CSS hidden-text detection, and an extensibility layer for neural feature providers and ANN architectures (including multi-head attention pooling), alongside several neural training-stability fixes. Recommended upgrade for all users, and especially for anyone running 4.1.0."}')}}]);