java

JDK 27.0.1 Release Notes

Java SE 27.0.1 - Bundled Patch Release (BPR) - Bug Fixes and Updates

The following sections summarize changes made in all Java SE 27.0.1 BPR releases. The BPR releases are listed below in date order, most current BPR first. Note that bug fixes in previous BPRs are also included in the current BPR.

 

Changes in Java SE 27.0.1.0.1

The 27.0.1.0.1 BPR is available to all users here.

Bug Fixes

Release date: October 20, 2026
BugId Category Subcategory Summary
JDK-8392377 core-libs java.time (tz) Update Timezone Data to 2026d
JDK-8392519 core-libs java.util:i18n Cherry-pick metazone changes from CLDR for tzdata2026d, for JDK update release
JDK-8392526 core-libs java.util:i18n Cherry-pick BCP 47 time zone changes from CLDR for tzdata2026d, for JDK update releases
JDK-8393337 core-libs java.time (tz) Update Timezone Data to 2026e
JDK-8393344 core-libs java.util:i18n Cherry-pick metazone changes from CLDR to support tzdata2026e for JDK update releases
JDK-8392538 core-libs java.util:i18n Align the JDK with Microsoft's new timezone names for British Columbia/Alberta
JDK-8393848 core-libs java.util:i18n Align the JDK with Microsoft's new timezone name for Manitoba

Java™ SE Development Kit 27, Update 27.0.1 (JDK 27.0.1)

October 20, 2026

The full version string for this update release is 27.0.1+9 (where "+" means "build"). The version number is 27.0.1. This JDK conforms to version 27 of the Java SE Specification (JSR 402 2026-09-15).

 

IANA TZ Data 2026c

JDK 27.0.1 contains IANA time zone data 2026c which contains the following changes:

  • Alberta moved to permanent -06 on 2026-06-18.
  • Morocco moves to permanent +00 on 2026-09-20.

For more information, refer to Timezone Data Versions in the JRE Software.

 

Security Baselines

The security baselines for the Java Runtime Environment (JRE) at the time of the release of JDK 27.0.1 are specified in the following table:

JRE Family Version JRE Security Baseline (Full Version String)
2727.0.1+9
2525.0.5+9
2121.0.13+10
1717.0.21+9
1111.0.33+9
81.8.0_511-b09

 

Keeping the JDK up to Date

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 27.0.1) be used after the next critical patch update scheduled for November 17, 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.

 

Other Notes

core-libs/java.net
➜ HttpServer Validates the Host Request Header (JDK-8386525 (not public))

The com.sun.net.http.HttpServer has been updated to validate the Host request header as described in RFC 9112. HTTP/1.1 requests without a Host header or with multiple Host headers are now rejected with an HTTP 400 Bad Request response.

The validation can be disabled by setting the system property sun.net.httpserver.disableHostValidation to true.

core-libs/java.sql
➜ Clarification of WebRowSet.readXml Exception Behavior (JDK-8383301 (not public))

The implementation of the WebRowSet.readXml methods has been updated to consistently report XML parsing and validation failures as SQLException.

WebRowSet.readXml validates XML input against the standard WebRowSet XML schema. Applications should expect malformed XML, schema validation failures, unsupported external entities, and other XML processing errors to be reported as SQLException. Validation can be disabled by setting the system property jdk.sql.rowset.webrowsetValidation to false.

The existing method signatures remain unchanged. No specification changes are included in this update.

core-libs/javax.naming
➜ Extend the Scope of com.sun.jndi.ldap.object.trustSerialData System Property to cover RMI URL References Obtained From an LDAP Context (JDK-8382407 (not public))

The scope of the com.sun.jndi.ldap.object.trustSerialData system property is extended to cover transparent processing of URL RMI References obtained from an LDAP context.

A URL context factory is a special type of ObjectFactory that will be used to look up an object referred to from a JNDI javax.naming.Reference that does not specify any factory name, but contains a simple reference address in the form of a URL string. When deserialization of Java objects from LDAP is disabled, the JDK built-in implementation of the JNDI/LDAP provider will no longer transparently use any URL context factory when processing Reference objects containing a URL reference whose scheme is rmi.

To make it possible to have a finer-grain control over which URL schemes should be disabled when processing URL string reference addresses from the built-in JNDI/LDAP provider, a new system property, jdk.jndi.ldap.disabledURLSchemes, is introduced. The value of this property is a comma-separated list of URL schemes that are disabled. The JDK built-in implementation of the JNDI/LDAP provider will no longer transparently use any URL context factory when processing Reference objects containing a URL reference whose scheme corresponds (case insensitively) to one of the schemes in this list of disabled schemes. The default value for that property is "rmi" if trustSerialData is false (the default), and empty if trustSerialData is true. If a custom value for this new property is provided on the Java command line then only schemes listed in that property value are disabled, regardless of the value of trustSerialData.

If rmi is included in this list (the default when no custom values have been supplied for com.sun.jndi.ldap.object.trustSerialData or jdk.jndi.ldap.disabledURLSchemes), then a javax.naming.Reference object will be returned to the application instead of the object that would have been created by processing the RMI reference and looking up its URL from the context returned by a URL context factory.

An application that depends on following RMI URLs contained in a Reference obtained from a JNDI/LDAP context may need to process the Reference object explicitly, or provide a custom value for the jdk.jndi.ldap.disabledURLSchemes system property that does not include the rmi scheme.

An application that wants to prevent transparent processing of other kinds of URL schemes can now do so by supplying a custom value for the jdk.jndi.ldap.disabledURLSchemes system property that also includes them.

security-libs/java.security
➜ LuxTrust Global Root CA Removed (JDK-8387123)

The following root certificate has been removed from the cacerts keystore:

+ alias name "luxtrustglobalrootca [jdk]"

  Distinguished Name: CN=LuxTrust Global Root, O=LuxTrust s.a., C=LU

 

tools/jshell
➜ New JShell Remote Agent Launch Protocol (JDK-8384736 (not public))

The way JShell's remote agents are invoked has changed. Existing agents will need to be updated to use the new protocol. See the jdk.jshell.execution.RemoteExecutionControl JavaDoc API documentation for the new protocol.

xml/jaxp
➜ JAXP Templates Class Deserialization Is Disabled (JDK-8384654 (not public))

Deserialization of the com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl class is now disabled by default. (This is an internal class that implements the javax.xml.transform.Templates interface.) An application attempting to deserialize an instance of this class will receive UnsupportedOperationException. To re-enable deserialization of this class, set the system property jdk.xml.enableTemplatesImplDeserialization to true. To take effect, this property must be set on the command line, in the jaxp.properties file, or in a user-defined JAXP configuration file.

 

Fixes

This release contains fixes for security vulnerabilities described in the Oracle Critical Patch Update.

➜ Issues fixed in 27.0.1:
# JBS Component/Subcomponent Summary
1JDK-8390380core-libs/java.util:i18nCherry-pick metazone changes from CLDR to support tzdata2026c for JDK update releases
2JDK-8388080hotspot/compilerIncrease static size of some stubs for APX code
3JDK-8386852hotspot/compilerLower peak throughput with AOTCache
4JDK-8385454hotspot/gcProvide more NUMA related information in hsinfo/hserr files
5JDK-8385817tools/jconsoleHeadless jdk still contains bin/jconsole