ktorio/ktor 3.4.2 on GitHub

Published 27 March 2026

KTOR-9327 Curl: The WebSockets maxFrameSize option does not have an effect
KTOR-9383 CaseInsensitiveString: reduce allocations
KTOR-9385 Netty: Allocation micro-optimizations
KTOR-9403 Darwin: Unnecessary ByteArray copy for each received response chunk
KTOR-9412 KDoc for formFieldLimit documents incorrect default value (64 KB instead of 50 MiB)

KTOR-9351 OpenAPI: Incorrect schema generated for nested classes with lists
KTOR-9361 WebSockets: JsWebSocketSession._closeReason is completed twice
KTOR-9437 Fix GraalVM Compatibility
KTOR-9424 Logging: OkHttp format should log the full requested URL
KTOR-8540 Logging: IllegalStateException is thrown when response is cached and deserialization fails
KTOR-9370 OpenAPI: NoSuchMethodError - getLOCAL_FUNCTION_FOR_LAMBDA with Kotlin 2.3.20-*
KTOR-9421 Netty: active SSE connection blocks HTTP/2 response flushing for other requests
KTOR-3390 JS browser: "Failed to execute 'digest' on 'SubtleCrypto'" error when using digest auth
KTOR-5977 Compression: The encoders buffer streaming response
KTOR-9393 Certificate pinning matches against all pins instead of hostname-scoped pins
KTOR-8751 DI: AmbiguousDependencyException when named dependency is overridden in testApplication
KTOR-9039 Bearer Auth: Request body transformed with jsonIO isn't sent over again after refreshToken request
KTOR-9404 Darwin: Memory leak in KtorNSURLSessionDelegate
KTOR-9399 LinkageError when running Ktor app with development mode inside Spring Boot / Amper fat-JAR
KTOR-9402 NoSuchMethodError on RawWebSocket after 3.4.0
KTOR-9372 Frame.Text.readText() causes infinite loop and 100% CPU on Kotlin/Native when WebSocket frame data is malformed or connection drops unexpectedly
KTOR-9387 ZstdEncoder decode fails when source data is split into multiple Zstd frames