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High 7.5Published May 12, 2026

CVE-2026-44241Micronaut Framework: Unbounded formattersCache in TimeConverterRegistrar Allows Memory Exhaustion via Accept-Language Header

Updated under an hour ago ()

Does this affect you?

It affects micronaut-projects micronaut-core. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-400
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
GitHub_M
NVD analysis
Deferred
Record last updated
Jul 9, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
micronaut-projects micronaut-core
micronaut_projects:micronaut_core (from the name)
from 4.3.0, < 4.10.22; from 3.10.0, < 3.10.6; before 3.8.14
CNA record

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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