Sourced from io.ktor:ktor-client-cio's releases.

3.4.3

Published 22 April 2026

Bugfixes

• KTOR-9451 OpenAPI schema inference not working for custom nested generics
• KTOR-9490 OpenAPI: Self-referential schema $ref uses FQN while schema is registered with a simple name
• KTOR-9463 OpenAPI: schema inference StackOverflow
• KTOR-8938 WebSockets: WebSockets handler does not inherit server coroutine context
• KTOR-8989 Shared engine is closed when a client created with config method is closed
• KTOR-9485 Apache5: FutureCallback never called, breaking Java agent instrumentation
• KTOR-9497 Darwin: SIGABRT crash when close() races with in-flight execute() since 3.4.2
• KTOR-9431 SuspendFunctionGun: ThreadContextElement leaks across requests when interceptor suspends
• KTOR-9423 CannotTransformContentToTypeException leaks internal class names in response body
• KTOR-9461 Incorrect link to the OWASP cheatsheet in the KDoc for CSRF plugin
• KTOR-9476 Unable to update/remove session data if no response content
• KTOR-9343 HttpRequestLifecycle plugin with cancelCallOnClose on, cancels subsequent requests when CallLogging plugin with callIdMdc is installed

Sourced from io.ktor:ktor-client-cio's changelog.

3.4.3

Published 22 April 2026

Bugfixes

• KTOR-9451 OpenAPI schema inference not working for custom nested generics
• KTOR-9490 OpenAPI: Self-referential schema $ref uses FQN while schema is registered with a simple name
• KTOR-9463 OpenAPI: schema inference StackOverflow
• KTOR-8938 WebSockets: WebSockets handler does not inherit server coroutine context
• KTOR-8989 Shared engine is closed when a client created with config method is closed
• KTOR-9485 Apache5: FutureCallback never called, breaking Java agent instrumentation
• KTOR-9497 Darwin: SIGABRT crash when close() races with in-flight execute() since 3.4.2
• KTOR-9431 SuspendFunctionGun: ThreadContextElement leaks across requests when interceptor suspends
• KTOR-9423 CannotTransformContentToTypeException leaks internal class names in response body
• KTOR-9461 Incorrect link to the OWASP cheatsheet in the KDoc for CSRF plugin
• KTOR-9476 Unable to update/remove session data if no response content
• KTOR-9343 HttpRequestLifecycle plugin with cancelCallOnClose on, cancels subsequent requests when CallLogging plugin with callIdMdc is installed

• 5d9a998 Release 3.4.3 (#5547)
• 6a11a76 KTOR-8989 Close or cancel engine only when the client reference count… (#5525)
• 3acb8ea KTOR-8938 Inherit server coroutine context in WebSocket session (#5426)
• cec7d38 Fix flaky test failures on native platforms (#5485)
• bd8bea1 KTOR-9507 Update Jackson to 2.21 and 3.1.0
• 5e29515 KTOR-9507 Update netty to 4.2.12
• 733b8e1 KTOR-9373 Make ConcurrentMap iteration safe on Native (#5407)
• 1f83f21 KTOR-9451 Support nested generic types (#5500)
• 2440990 Apache 5 Client. Don't ignore resultCallback (#5526)
• 430f320 Follow-up: KTOR-9497 Preventing a fatal crash in DarwinSession on close (#5533)
• Additional commits viewable in compare view