<section name="Release 13.0.0">

<div class="releaseDate">04.01.2026</div>

<p>Breaking backward compatibility:</p>

<ul>

<li>

Use jdk21 as minimial required.

Author: Amit Kumar Deohoria, Roman Ivanov

<a href="https://github.com/checkstyle/checkstyle/issues/17430">#17430</a>

</li>

</ul>

<p>Bug fixes:</p>

<ul>

<li>

Remove duplicate violations in WhitespaceAfter and WhitespaceAround in sun_checks.xml.

Author: vivek-0509

<a href="https://github.com/checkstyle/checkstyle/issues/18409">#18409</a>

</li>

</ul>

<p>Notes:</p>

<ul>

<li>

jdk21: activate MissingNullCaseInSwitch for checkstyle project.

Author: Monu Chaudhary

<a href="https://github.com/checkstyle/checkstyle/issues/17428">#17428</a>

</li>

<li>

Resolve Pitest Suppressions - imports.

Author: Daniel Gao

<a href="https://github.com/checkstyle/checkstyle/issues/18034">#18034</a>

</li>

<li>

Conversion to Enhance Switch for AnnotationUseStyle Check Causing Jacoco Coverage Issue.

Author: Roman Ivanov

<a href="https://github.com/checkstyle/checkstyle/issues/17674">#17674</a>

</li>

<li>

Convert eligible classes to records.

Author: smita_1078, Roman Ivanov

<a href="https://github.com/checkstyle/checkstyle/issues/17299">#17299</a>

</li>

<li>

pitest: increase mutation coverage for indentation profile to 100%.

Author: vivek-0509

<a href="https://github.com/checkstyle/checkstyle/issues/6294">#6294</a>

</li>

<li>

Resolve Pitest Suppressions - filters.

Author: aclfe

<a href="https://github.com/checkstyle/checkstyle/issues/18023">#18023</a>

</li>

<li>

Fix xdocs Examples AST Consistency Test (Reduce suppressions list).

Author: Zaheer Ahmad

<a href="https://github.com/checkstyle/checkstyle/issues/18435">#18435</a>

</li>

<li>

EmptyLineSeparator ignores configured tokens: reports violations for unlisted tokens

and skips listed ones.

Author: Aman Baliyan

<a href="https://github.com/checkstyle/checkstyle/issues/17568">#17568</a>

</li>

<li>

Enforce file size on Java inputs.

Author: Monu Chaudhary

<a href="https://github.com/checkstyle/checkstyle/issues/11163">#11163</a>

</li>

<li>

Store SARIF schema locally to avoid external network dependency.

Author: vivek-0509

<a href="https://github.com/checkstyle/checkstyle/issues/18448">#18448</a>

</li>

<li>

Update `JavadocCommentsTokenTypes.java` to new format of AST print.

Author: 0xChaitanya

<a href="https://github.com/checkstyle/checkstyle/issues/17882">#17882</a>

</li>

</ul>

</section>