Withdrawn by the publisher.

Affected: CleanStart: akhq

Package akhq version 0.27.1-r5 fixes 27 vulnerabilities: CVE-2026-58062, CVE-2026-59638, CVE-2026-59646, CVE-2026-12802, CVE-2026-59639...

Micronaut Framework is a JVM-based full stack Java framework designed for building modular, easily testable JVM applications. From 4.3.0 to before 4.10.22, 3.10.6, and 3.8.14, TimeConverterRegistrar caches DateTimeFormatter instances in an unbounded ConcurrentHashMap<String, DateTimeFormatter> whose key is derived from the @Format annotation pattern concatenated with the locale from the HTTP Accept-Language header. Because Locale.forLanguageTag() accepts arbitrary BCP 47 private-use extensions (en-x-a001, en-x-a002, …), an unauthenticated attacker can generate an unlimited number of unique cache keys by sending requests with novel locale tags, growing the cache until heap memory is exhausted and the JVM crashes. This vulnerability is fixed in 4.10.22, 3.10.6, and 3.8.14.

Affected: Maven: io.micronaut:micronaut-context

## Summary

`TimeConverterRegistrar` caches `DateTimeFormatter` instances in an unbounded `ConcurrentHashMap<String, DateTimeFormatter>` whose key is derived from the `@Format` annotation pattern concatenated with the locale from the HTTP `Accept-Language` header. Because `Locale.forLanguageTag()` accepts arbitrary BCP 47 private-use extensions (`en-x-a001`, `en-x-a002`, …), an unauthenticated attacker can generate an unlimited number of unique cache keys by sending requests with novel locale tags, growing the cache until heap memory is exhausted and the JVM crashes. This is structurally identical to the recently patched GHSA-2hcp-gjrf-7fhc (`DefaultHtmlErrorResponseBodyProvider`), but `TimeConverterRegistrar.formattersCache` was not covered by that fix.

## Details

The vulnerable cache is declared in `context/src/main/java/io/micronaut/runtime/converters/time/TimeConverterRegistrar.java` at line 123:

```java // TimeConverterRegistrar.java:123 private final Map<String, DateTimeFormatter> formattersCache = new ConcurrentHashMap<>(); ```

The `getFormatter` method at line 434 inserts into this map with no eviction or size limit:

```java // TimeConverterRegistrar.java:434-443 private DateTimeFormatter getFormatter(String pattern, ConversionContext context) { var key = pattern + context.getLocale(); // locale from Accept-Language header var cachedFormatter = formattersCache.get(key); if (cachedFormatter != null) { return cachedFormatter; } v…