Release date: April 21, 2026
The full version string for this update release is 1.8.0_491-perf-b8 (where "b" means "build"). The version number is 1.8.0_491-perf.
JDK 8u491 contains IANA time zone data 2026a which contains the following changes since the previous update.
For more information, refer to Timezone Data Versions in the JRE Software.
The security baselines for the Java Runtime at the time of the release of JDK 8u491 are specified in the following table:
| Java Family Version | Security Baseline (Full Version String) |
|---|---|
| 8 | 1.8.0_491-perf-b8 |
Oracle recommends that the JDK is updated with each Critical Patch Update. In order to determine if a release is the latest, the Security Baseline page can be used to determine which is the latest version for each release family.
Critical patch updates, which contain security vulnerability fixes, are announced one year in advance on Critical Patch Updates, Security Alerts and Bulletins. It is not recommended that this JDK (version 8u491) be used after the next critical patch update scheduled for July 21, 2026.
Java Management Service, available to all users, can help you find vulnerable Java versions in your systems. Java SE Subscribers and customers running in Oracle Cloud can use Java Management Service to update Java Runtimes and to do further security reviews like identifying potentially vulnerable third party libraries used by your Java programs. Existing Java Management Service user click here to log in to your dashboard. The Java Management Service Documentation provides a list of features available to everyone and those available only to customers. Learn more about using Java Management Service to monitor and secure your Java Installations.
For systems unable to reach the Oracle Servers, a secondary mechanism expires this JRE (version 8u491) on 2026-08-21. After either condition is met (new release becoming available or expiration date reached), the JRE will provide additional warnings and reminders to users to update to the newer version. For more information, see 23.1.2 JRE Expiration Date in the Java Platform, Standard Edition Deployment Guide.
A new system property, jdk.tls.server.newSessionTicketCount, sets the number of TLSv1.3 resumption tickets sent by a JSSE server per session. It can be set on the command line with -Djdk.tls.server.newSessionTicketCount=#, where # ranges from 0 to 10. The default is 1.
For more details, see Customizing JSSE.
The keytool command reads passwords from the system console to prevent them from being displayed on the screen. However, the console is usually available only when both the standard input and output streams are not redirected. Previously, if the standard output stream was redirected into a file or another command, the console was unavailable and the input password was echoed on the screen. This enhancement improves password handling to ensure that the password is not displayed on the screen even if the standard output stream is redirected. This enhancement has also been made to the jarsigner command and the JAAS TextCallbackHandler API.
The G1 garbage collector now throws an OutOfMemoryException (OOME) when the garbage collection overhead is more than GCTimeLimit percent (default value 98) and the free Java heap is less than GCHeapFreeLimit percent (default value 2) for five consecutive garbage collections.
This feature is enabled by default. It can be disabled using the -XX:-UseGCOverheadLimit option.
The implementation mirrors the functionality already provided by the Parallel garbage collector. However there may be differences in the exact conditions for the OOME triggers as G1 calculates garbage collection overhead and free Java heap slightly differently.
A new security property named jdk.crypto.disabledAlgorithms has been introduced to disable algorithms for JCE/JCA cryptographic services. Initially, this property only supports the Cipher, KeyStore, MessageDigest, and Signature services. This property is defined in the java.security file and initially no algorithms are disabled by default. However, this may change in the future. This security property can be overridden by a system property of the same name if applications need to re-enable algorithms.
See Disabled and Restricted Cryptographic Algorithms for more information.
The JDK will stop trusting TLS server certificates issued after March 17, 2026 and anchored by Chunghwa root certificates, in line with similar plans announced by Google and Mozilla.
TLS server certificates issued on or before March 17, 2026 will continue to be trusted until they expire. Certificates issued after that date, and anchored by the Certificate Authority listed in the table below, will be rejected.
The restrictions are enforced in the JDK implementation (the SunJSSE Provider) of the Java Secure Socket Extension (JSSE) API. A TLS session will not be negotiated if the server's certificate chain is anchored by any of the Certificate Authorities in the table below and the certificate has been issued after March 17, 2026.
An application will receive an exception with a message indicating the trust anchor is not trusted, for example:
"TLS Server certificate issued after 2026-03-17 and anchored by a distrusted legacy Chunghwa root CA: OU=ePKI Root Certification Authority, O="Chunghwa Telecom Co., Ltd." C=TW"
The JDK can be configured to trust these certificates again by removing "CHUNGHWA_TLS" from the jdk.security.caDistrustPolicies security property in the java.security configuration file.
The restrictions are imposed on the following Chunghwa Root certificates included in the JDK:
| Distinguished Name | SHA-256 Fingerprint |
|---|---|
| OU=ePKI Root Certification Authority, O="Chunghwa Telecom Co., Ltd.", C=TW | C0:A6:F4:DC:63:A2:4B:FD:CF:54:EF:2A:6A:08:2A:0A:72:DE:35:80:3E:2F:F5:FF:52:7A:E5:D8:72:06:DF:D5 |
You can also use the keytool utility from the JDK to print out details of the certificate chain, as follows:
keytool -v -list -alias <your_server_alias> -keystore <your_keystore_filename>
If any of the certificates in the chain are issued by one of the root CAs in the table above are listed in the output you will need to update the certificate or contact the organization that manages the server.
| # | BugId | Component | Summary |
|---|---|---|---|
| 1 | JDK-8372048 | client-libs/java.awt | Performance improvement on Linux remote desktop |
| 2 | JDK-8375063 | client-libs/java.awt | Update Libpng to 1.6.54 |
| 3 | JDK-8372977 | client-libs/java.awt | Unnecessary gthread-2.0 loading |
| 4 | JDK-8366261 | core-libs/java.io | Provide utility methods for sun.security.util.Password |
| 5 | JDK-8301875 | core-libs/java.util | java.util.TimeZone.getSystemTimeZoneID uses C library default file mode |
| 6 | JDK-8361117 | hotspot/compiler | SIGSEGV in LShiftLNode::Ideal due to unexpected dead node |
| 7 | JDK-8370325 | hotspot/gc | G1: Disallow GC for TLAB allocation |
| 8 | JDK-8365972 | hotspot/jfr | JFR: ThreadDump and ClassLoaderStatistics events may cause back to back rotations |
| 9 | JDK-8303475 | hotspot/runtime | potential null pointer dereference in filemap.cpp |
| 10 | JDK-8375549 | security-libs/java.security | ConcurrentModificationException if jdk.crypto.disabledAlgorithms has multiple entries with known oid |
| 11 | JDK-8244336 | security-libs/java.security | Restrict algorithms at JCE layer |
| 12 | JDK-8374555 | security-libs/java.security | No need for visible input warning in s.s.u.Password when not reading from System.in |
| 13 | JDK-8334670 | security-libs/javax.net.ssl | SSLSocketOutputRecord buffer miscalculation |
| 14 | JDK-8311644 | security-libs/javax.net.ssl | Server should not send bad_certificate alert when the client does not send any certificates |
| 15 | JDK-8336695 | xml/jaxp | Update Commons BCEL to Version 6.10.0 |