This is closely related to but distinct from JDK-8266082.

In the following example, enabling -Xdoclint:all causes javac to crash.

I think the underlying problem is closely related to JDK-8266082, but that fixes the issue for annotations on method parameters in a @link, and this is occurring for a class type with an annotated type parameter.

=== A.java
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/** An annotation. */
@Target(ElementType.TYPE_PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@interface A {}
=== T.java
/** {@link java.util.List<@A Object>} */
class T {
  /** A constructor. */
  private T() {}
}
===

$ javac -fullversion -Xdoclint:all A.java T.java
javac full version "26-ea+19-1957"
An exception has occurred in the compiler (26-ea). Please file a bug against the Java compiler via the Java bug reporting page (https://bugreport.java.com) after checking the Bug Database (https://bugs.java.com) for duplicates. Include your program, the following diagnostic, and the parameters passed to the Java compiler in your report. Thank you.
java.lang.AssertionError
        at jdk.compiler/com.sun.tools.javac.util.Assert.error(Assert.java:155)
        at jdk.compiler/com.sun.tools.javac.util.Assert.checkNonNull(Assert.java:62)
        at jdk.compiler/com.sun.tools.javac.comp.Annotate.fromAnnotations(Annotate.java:163)
        at jdk.compiler/com.sun.tools.javac.comp.Annotate.lambda$annotateTypeSecondStage$0(Annotate.java:1051)
        at jdk.compiler/com.sun.tools.javac.comp.Annotate.flush(Annotate.java:194)
        at jdk.compiler/com.sun.tools.javac.comp.Attr.attribClass(Attr.java:5367)
        at jdk.compiler/com.sun.tools.javac.comp.Attr.attrib(Attr.java:5303)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.attribute(JavaCompiler.java:1360)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:982)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:319)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:178)
        at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:66)
        at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:52)