Last updated: April 13, 2016
Java Critical Patch Update (CPU) and Patch Set Update (PSU)
Beginning with the scheduled October 2014 update to Java SE 7, Oracle will release both a Java Critical Patch Update (CPU) and a Java Patch Set Update (PSU). Both updates will be released at the same time. To avoid any potential confusion, Oracle specifically states that the Java Critical Patch Update (CPU) release will apply to most users:
Oracle strongly recommends that all Java SE users upgrade to the latest CPU release available for a release family. Most users should choose the CPU release.
With regard to the Patch Set Update, users would only need to use it if they need a fix for a specific bug contained in the release notes for the version:
Users should only use the corresponding PSU release if they are being impacted by one of the additional bugs fixed in that version as noted in the release notes.
The subsequent CPU release will contain all of the fixes from the current PSU. For this reason, organizations should test the current PSU in their environment in anticipation of these fixes being included in the next CPU.
Oracle recommends the Java Critical Patch Update for most users because it contains the fixes for security vulnerabilities as well as critical bug fixes. Users should update to the latest CPU as soon as possible after it becomes available. The PSU also contains the same fixes for security vulnerabilities and critical bug fixes as the CPU, but it also contains non-critical fixes. Users should review the release notes for each new release to see if the PSU applies to them. Please note that Oracle will only be releasing a PSU for the current version of Java that is auto updating.
Users should expect that Oracle will release a PSU to accompany the scheduled CPU from October 2014 forward:
Starting in October 2014 with the release of Java SE 7u71 (CPU) and Java SE 7u72 (PSU), Oracle will release a corresponding PSU release with each CPU release for the default Java version. This will enable organizations and developers that need to obtain Java versions that have the non-critical fixes with greater frequency and on a set schedule in addition to the security fixes contained in the corresponding CPU.
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