CVE-2026-44242

Micronaut Framework: Unbounded bundleCache in ResourceBundleMessageSource Allows Memory Exhaustion via Accept-Language Header

LOW
3.7
CVSS Score
Published: May 12, 2026 at 09:17 PM UTC
Updated: October 26, 2026 at 02:10 PM UTC
1 product affected across 1 vendorMicronaut

Using micronaut-core by micronaut-projects?

Get instant alerts when new vulnerabilities affect micronaut-core - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
LOW3.7
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

Micronaut Framework is a JVM-based full stack Java framework designed for building modular, easily testable JVM applications. Prior to 4.10.22, the bundleCache is keyed by (Locale, baseName) where the locale originates from the HTTP Accept-Language header. In applications that explicitly register a ResourceBundleMessageSource bean and serve HTML error responses, an unauthenticated attacker can exhaust heap memory by sending requests with large numbers of unique Accept-Language values, each causing a new entry in the unbounded bundleCache. This vulnerability is fixed in 4.10.22.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.10.22
Affected range stops below 4.10.22, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

3.7LOWGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-400

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card