What's Changed

• Revert "Eliminate redundant bounds checks in CompositeByteBuf accessors" by @chrisvest in #16550

Full Changelog: netty-4.2.11.Final...netty-4.2.12.Final

Security

• CVE-2026-33871, HTTP/2 CONTINUATION Frame Flood Denial of Service
• CVE-2026-33870, HTTP Request Smuggling via Chunked Extension Quoted-String Parsing

What's Changed

• Update to latest JDK 26 EA release by @normanmaurer in #16230
• HTTP3: Allow to support non-standard HTTP3 settings by @normanmaurer in #16171
• Fix Incorrect nanos-to-millis conversion in epoll_wait EINTR retry loop by @adwsingh in #16245
• Allocate one large segment and slice for each MsgHdrMemory by @dreamlike-ocean in #16234
• Make RefCntOpenSslContext.deallocate more robust by @chrisvest in #16253
• Epoll: Fix excessive CPU usage when Channel is only registered but no… by @normanmaurer in #16250
• Update to gcc for arm 10.3-2021.07 by @m1ngyuan in #16255
• Add acmeIdentifier extension support to pkitesting by @chrisvest in #16256
• Update JDK versions to latest patch releases by @m1ngyuan in #16254
• Avoid allocation in HttpObjectEncoder.addEncodedLengthHex method by @doom369 in #16241
• Automatic backporting workflow from 4.1 to 4.2 by @chrisvest in #16269
• Revert "Automatic backporting workflow from 4.1 to 4.2" by @chrisvest in #16270
• HTTP2: Correctly account for padding when decompress by @normanmaurer in #16264
• Automatic backporting workflow from 4.1 to 4.2 by @chrisvest in #16271
• Automatic backporting workflow from 4.1 to 4.2 by @chrisvest in #16273
• Backport PRs must be created with personal access tokens by @chrisvest in #16276
• Expose QuicSslContextBuilder::sni by @ZeroErrors in #16178
• Add more porting workflows by @chrisvest in #16275
• Add more porting workflows by @chrisvest in #16283
• Remove the unpooled allocator from test permutations by @chrisvest in #16282
• Some polishing of the porting workflows by @chrisvest in #16288
• Allow to set destination connection id when creating a client side QuicheChannel by @normanmaurer in #16286
• Update to latest JDK26 EA build by @normanmaurer in #16295
• Add javadoc to clarify responsibility of the user when generating the remote connection id by @normanmaurer in #16293
• Make the build run faster by @chrisvest in #16290
• Fix IDE warnings in SslHandler by @doom369 in #16237
• Decrease Long allocations and map.put calls in ReferenceCountedOpenSllEngine in handshake() method by @doom369 in #16242
• Support boringssl SSLCredential API by @jmcrawford45 in #15919
• Fix high-order bit aliasing in HttpUtil.validateToken by @furkanvarol in #16279
• Improve multi-byte access performance when UNALIGNED availability is unknown by @Songdoeon in #16207
• Avoid unnecessary SSL.getVersion() call and string allocation in ReferenceCountedOpenSslEngine by @doom369 in #16278
• Support more branch freedom for auto-porting by @chrisvest in #16300
• fix: the precedence of + is higher than >> by @cuiweixie in #16312
• AdaptiveByteBufAllocator: make sure byteBuf.capacity() not greater than byteBuf.maxCapacity() by @laosijikaichele in #16309
• Fix flaky PooledByteBufAllocatorTest by @chrisvest in #16313
• Fix pooled arena accounting tests by @chrisvest in #16321
• Fix RunInFastThreadLocalThreadExtension by @chrisvest in #16314
• AdaptivePoolingAllocator: call unreserveMatchingBuddy(...) if byteBuf initialization failed by @laosijikaichele in #16327
• Recycler should not use thread locals unless they get cleaned up by @chrisvest in #16315
• OpenSSL: Don't leak OpenSslKeyManagerProvider on exception by @normanmaurer in #16337
• IoUring: Only complete deregistration promise once we received all co… by @normanmaurer in #16330
• Mark LoggingHandlerTest with @isolated to fix flaky build by @normanmaurer in #16338
• Fix flaky HTTP/2 test by @chrisvest in #16342
• Fix HTTP/2 push frame test by @chrisvest in #16343
• Fix flaky RenegotiateTest by @chrisvest in #16351
• IoUring: Don't use RDHUP for non stream Channel implementations by @normanmaurer in #16345
• SSL test: Don't depend on property value in test by @normanmaurer in #16346
• Fix flaky AbstractSingleThreadEventLoopTest by @chrisvest in #16352
• Use headers.setInt() in HttpObjectAggregator instead of set() and use concrete version of String.valueOf in CharSequenceValueConverter by @doom369 in #16239
• IoUring: Fix buffer leak in DatagramChannel implementation when recv … by @normanmaurer in #16359
• Don't assume CertificateFactory is thread-safe by @chrisvest in #16350
• AdaptivePoolingAllocator: assign a more explicit value to BuddyChunk.freeListCapacity by @laosijikaichele in #16334
• Fix leak in SniHandlerTest by @chrisvest in #16367
• Add more diagnostic points to PooledByteBufAllocatorTest.createNewThr… by @chrisvest in #16365
• Stabilize AbstractByteBufTest.testBytesInArrayMultipleThreads by @chrisvest in #16370
• Avoid unnecessary Long.toString() allocation in HttpObjectDecoder by @doom369 in #16344
• Remove reference counting from size classed chunks by @franz1981 in #16306
• Stabilize AbstractByteBufTest.testToStringMultipleThreads by @chrisvest in #16380
• Swap conditions to avoid native calls in ReferenceCountedOpenSslEngine.rejectRemoteInitiatedRenegotiation by @doom369 in #16389
• Remove duplicated contains calls in WebSockets by @doom369 in #16388
• IoUring: Reduce unnecessary io_uring_enter syscalls on non-blocking path by @dreamlike-ocean in #16259
• Fix NioIoHandlerTest on macOS by @chrisvest in #16396
• LocalChannel: Remove dependency on SingleThreadEventExecutor by @normanmaurer in #16393
• Fix autoport fetching into the existing branch by @chrisvest in #16403
• HTTP2: Pass the correct number of arguments when logging goaway by @normanmaurer in #16392
• Revert "Fix autoport fetching into the existing branch" by @chrisvest in #16410
• Fix HttpObjectAggregator leaving connection stuck after 413 with AUTO (#16280) by @chrisvest in #16401
• Fix autoport fetching into the existing branch - again by @chrisvest in #16411
• Fix typo in AbstractEpollChannel: 'inital' → 'initial' by @nikitanagar08 in #16415
• Capture why threads get stuck in testCopyMultipleThreads0 by @chrisvest in #16404
• Local transport: shutdown hook should call closeNow to be conistent with what LocalIoHandler will call by @normanmaurer in #16406
• Remove unnecessary array access in DefaultAttributeMap.orderedCopyOnInsert by @doom369 in #16386
• Whitelist JMH annotation processing in microbench module by @laosijikaichele in #16428
• Fire the QuicChannel datagram extension event before the channel becomes active by @vietj in #16425
• HTTP2: Ensure preface is flushed in all cases by @normanmaurer in #16407
• Support QuicheQuicSslEngine hostname identification algorithm. by @vietj in #16426
• Fix client_max_window_bits parameter handling in permessage-deflate extension by @nikitanagar08 in #16424
• Fix UnsupportedOperationException in readTrailingHeaders by @furkanvarol in #16412
• IoUring: Fix io_uring writev infinite loop on kernels without SENDMSG_ZC support by @dreamlike-ocean in #16438
• Kqueue: Correctly handle registrations by @normanmaurer in #16439
• Kqueue: C...

Security

• CVE-2026-33871, HTTP/2 CONTINUATION Frame Flood Denial of Service
• CVE-2026-33870, HTTP Request Smuggling via Chunked Extension Quoted-String Parsing

What's Changed

• Fix Incorrect nanos-to-millis conversion in epoll_wait EINTR retry lo… by @normanmaurer in #16248
• Make RefCntOpenSslContext.deallocate more robust (#16253) by @normanmaurer in #16257
• Update to gcc for arm 10.3-2021.07 (#16255) by @normanmaurer in #16263
• HTTP2: Correctly account for padding when decompress by @normanmaurer in #16265
• Update JDK versions to latest patch releases (#16254) by @normanmaurer in #16267
• Backport 4.1: Automatic backporting workflow from 4.1 to 4.2 by @github-actions[bot] in #16274
• Backport 4.1: Backport PRs must be created with personal access tokens by @chrisvest in #16277
• Backport 4.1: Add more porting workflows by @netty-project-bot in #16284
• Backport 4.1: Some polishing of the porting workflows by @netty-project-bot in #16292
• Backport 4.1: Fix high-order bit aliasing in HttpUtil.validateToken by @netty-project-bot in #16303
• Auto-port 4.1: Support more branch freedom for auto-porting by @netty-project-bot in #16310
• fix: the precedence of + is higher than >> (#16312) by @chrisvest in #16316
• AdaptiveByteBufAllocator: make sure byteBuf.capacity() not greater th… by @chrisvest in #16320
• Auto-port 4.1: Fix flaky PooledByteBufAllocatorTest by @netty-project-bot in #16324
• Auto-port 4.1: Fix pooled arena accounting tests by @netty-project-bot in #16326
• Auto-port 4.1: Fix RunInFastThreadLocalThreadExtension by @netty-project-bot in #16328
• Auto-port 4.1: AdaptivePoolingAllocator: call unreserveMatchingBuddy(...) if byteBuf initialization failed by @netty-project-bot in #16331
• Auto-port 4.1: Mark LoggingHandlerTest with @isolated to fix flaky build by @netty-project-bot in #16340
• Auto-port 4.1: Fix flaky HTTP/2 test by @netty-project-bot in #16348
• Auto-port 4.1: Fix flaky RenegotiateTest by @netty-project-bot in #16355
• Auto-port 4.1: Fix HTTP/2 push frame test by @netty-project-bot in #16353
• SSL test: Don't depend on property value in test (#16346) by @normanmaurer in #16362
• Auto-port 4.1: Don't assume CertificateFactory is thread-safe by @netty-project-bot in #16364
• AdaptivePoolingAllocator: assign a more explicit value to BuddyChunk.freeListCapacity (#16334) by @chrisvest in #16368
• Auto-port 4.1: Add more diagnostic points to PooledByteBufAllocatorTest.createNewThr… by @netty-project-bot in #16372
• Fix leak in SniHandlerTest (#16367) by @normanmaurer in #16377
• Auto-port 4.1: Stabilize AbstractByteBufTest.testBytesInArrayMultipleThreads by @netty-project-bot in #16373
• Remove reference counting from size classed chunks (#16306) by @chrisvest in #16379
• Auto-port 4.1: Stabilize AbstractByteBufTest.testToStringMultipleThreads by @netty-project-bot in #16384
• Fix HttpObjectAggregator leaving connection stuck after 413 with AUTO… by @samlandfried in #16280
• Auto-port 4.1: Fix autoport fetching into the existing branch - again by @netty-project-bot in #16417
• Auto-port 4.1: Capture why threads get stuck in testCopyMultipleThreads0 by @netty-project-bot in #16419
• Auto-port 4.1: Remove unnecessary array access in DefaultAttributeMap.orderedCopyOnInsert by @netty-project-bot in #16421
• Auto-port 4.1: Whitelist JMH annotation processing in microbench module by @netty-project-bot in #16430
• Auto-port 4.1: HTTP2: Ensure preface is flushed in all cases by @netty-project-bot in #16432
• Auto-port 4.1: Fix UnsupportedOperationException in readTrailingHeaders by @netty-project-bot in #16437
• Auto-port 4.1: Fix client_max_window_bits parameter handling in permessage-deflate extension by @netty-project-bot in #16435
• Auto-port 4.1: Native transports: Fix possible fd leak when fcntl fails. by @netty-project-bot in #16446
• Auto-port 4.1: Kqueue: Fix undefined behaviour when GetStringUTFChars fails and SO_ACCEPTFILTER is supported by @netty-project-bot in #16448
• Auto-port 4.1: Kqueue: Possible overflow when using netty_kqueue_bsdsocket_setAcceptFilter(...) by @netty-project-bot in #16459
• Auto-port 4.1: Native transports: Fix undefined behaviour when GetStringUTFChars fails while open FD by @netty-project-bot in #16456
• Auto-port 4.1: Epoll: Add null checks for safety reasons by @netty-project-bot in #16463
• Auto-port 4.1: DnsNameResolver: Skip test if we can not bind TCP and UDP to the same port by @netty-project-bot in #16464
• Auto-port 4.1: Epoll: Use correct value to initialize mmsghdr.msg_namelen by @netty-project-bot in #16467
• Auto-port 4.1: Epoll: Fix support for IP_RECVORIGDSTADDR by @netty-project-bot in #16468
• Auto-port 4.1: AdaptivePoolingAllocator: remove ensureAccessible() call in capacity(int) method by @netty-project-bot in #16475
• Auto-port 4.1: AdaptivePoolingAllocator: Fix assertion for size class multiple of 32 by @netty-project-bot in #16497
• Epoll: setTcpMg5Sig(...) might overflow (#16511) by @normanmaurer in #16520
• Auto-port 4.1: JdkZlibDecoder: accumulate decompressed output before firing channelRead by @netty-project-bot in #16532
• Limit the number of Continuation frames per HTTP2 Headers by @normanmaurer in #13969
• Stricter HTTP/1.1 chunk extension parsing by @chrisvest in #16537

New Contributors

• @github-actions[bot] made their first contribution in #16274
• @samlandfried made their first contribution in #16280

Full Changelog: netty-4.1.131.Final...netty-4.1.132.Final