RELEASE NOTES: JDK 21.0.13

Notes generated: Wed Jul 01 06:56:58 CEST 2026

JEPs

None.

RELEASE NOTES

hotspot/compiler

Issue Description

Issue	Description
JDK-8341527	SHA3 Performance Improved The performance of the `MessageDigest` implementations that belong to the SHA3 family (SHA3-224, SHA3-256, SHA3-384, and SHA3-512) has been improved by 6-27%, depending on digested message length and on the platform used. An additional 30-40% can be experienced on AVX-512 capable platforms due to new intrinsic implementations on that platform.

SHA3 Performance Improved

The performance of the MessageDigest implementations that belong to the SHA3 family (SHA3-224, SHA3-256, SHA3-384, and SHA3-512) has been improved by 6-27%, depending on digested message length and on the platform used. An additional 30-40% can be experienced on AVX-512 capable platforms due to new intrinsic implementations on that platform.

security-libs/java.security

Issue Description

Issue	Description
JDK-8333867	SHA3 Performance Improved The performance of the `MessageDigest` implementations that belong to the SHA3 family (SHA3-224, SHA3-256, SHA3-384, and SHA3-512) has been improved by 6-27%, depending on digested message length and on the platform used. An additional 30-40% can be experienced on AVX-512 capable platforms due to new intrinsic implementations on that platform.

JDK-8333867

SHA3 Performance Improved

FIXED ISSUES

client-libs/java.awt

Priority	Bug	Summary
P4	JDK-8343739	Test java/awt/event/KeyEvent/ExtendedKeyCode/ExtendedKeyCodeTest.java failed: Wrong extended key code
P4	JDK-8372546	UnixMultiResolutionSplashTest.java fails intermittently on Ubuntu_24.04

core-libs

Priority	Bug	Summary
P3	JDK-8378180	Compiling OpenJDK with C23 C-Compiler gives warning: initialization discards ‘const’ qualifier from pointer target type

core-libs/java.nio

Priority	Bug	Summary
P4	JDK-8375294	(fs) Files.copy can fail with EOPNOTSUPP when copy_file_range not supported
P4	JDK-8384163	(so) SocketChannel.connect and finishConnect() exception messages could be improved

hotspot/compiler

Priority	Bug	Summary
P3	JDK-8341527	AVX-512 intrinsic for SHA3
P4	JDK-8310331	JitTester: Exclude java.lang.Math.random

hotspot/jfr

Priority	Bug	Summary
P4	JDK-8386345	Remove redundant @requires from TestGarbageCollectionEventWithZMinor

hotspot/runtime

Priority	Bug	Summary
P4	JDK-8383611	assert(count == os::processor_count() + 1) failed: invalid enumeration!
P4	JDK-8375125	assert(false) failed: "Attempting to acquire lock NativeHeapTrimmer_lock/nosafepoint out of order with lock ConcurrentHashTableResize_lock/nosafepoint-2 -- possible deadlock" when using native heap trimmer
P4	JDK-8364106	Include java.runtime.version in thread dump output
P4	JDK-8343698	Linux x86_64 lto build gives a lot of warnings and fails lto-wrapper: fatal error: make returned 2 exit status
P4	JDK-8372615	Many container tests fail when running rootless on cgroup v1

infrastructure

Priority	Bug	Summary
P3	JDK-8361950	Update to use jtreg 8
P3	JDK-8369488	Update to use jtreg 8.1
P3	JDK-8376355	Update to use jtreg 8.2.1
P4	JDK-8385508	Bump update version for OpenJDK: jdk-21.0.13

infrastructure/build

Priority	Bug	Summary
P4	JDK-8247690	RunTest does not support running of JTREG manual tests

security-libs/java.security

Priority	Bug	Summary
P3	JDK-8374886	CAInterop.java#microsoftrsa2017 test fails as EE certificate does not specify OCSP responder
P3	JDK-8338587	Internal XOF Methods for SHAKE128 and SHAKE256
P4	JDK-8381771	Add a check for DNS label not to end with a hyphen
P4	JDK-8385584	CAInterop.java#buypassclass3ca fails with Intermediate Root CA not found in the chain
P4	JDK-8381937	Make exceptions in Java_sun_security_mscapi_CKeyPairGenerator generateCKeyPair more specific
P4	JDK-8333867	SHA3 performance can be improved