# Micronaut has Unbounded \`bundleCache\` in \`ResourceBundleMessageSource\` that Allows Memory Exhaustion via \`Accept-Language\` Header

Advisory record · `GHSA-3rfq-4wpf-qqw3`

- **Identifiers:** `GHSA-3rfq-4wpf-qqw3` · `CVE-2026-44242`
- **State:** Confirmed
- **Severity:** CVSS 3.7 Low
- **Critical:** No
- **Weakness (CWE):** [CWE-400](https://cwe.mitre.org/data/definitions/400.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md)
- **Published:** 6 May 2026
- **Updated:** 30 Jun 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 6 May 2026, 19:57 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `io.micronaut:micronaut-inject` (Maven): affected `>=4.10.0, <4.10.22 || >=3.10.0, <3.10.6 || <3.8.14`; fixed in `4.10.22`, `3.10.6`, `3.8.14`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Micronaut's micronaut-inject package is affected in versions from 4.10.0 before 4.10.22, from 3.10.0 before 3.10.6, and before 3.8.14. An unauthenticated attacker can exhaust heap memory on applications that register a ResourceBundleMessageSource bean and serve HTML error responses, by sending requests with many unique Accept-Language values. Upgrade to 4.10.22, 3.10.6, or 3.8.14, depending on your release line.

Written 2 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 3.7 Low, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0026, the 17th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:20 UTC: First seen by agentprime
- 31 Oct 2026, 14:20 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-3rfq-4wpf-qqw3)

## Sources

- [GitHub Advisory Database: GHSA-3rfq-4wpf-qqw3](https://github.com/advisories/GHSA-3rfq-4wpf-qqw3)
- [OSV: GHSA-3rfq-4wpf-qqw3](https://osv.dev/vulnerability/GHSA-3rfq-4wpf-qqw3)
- <https://github.com/micronaut-projects/micronaut-core/security/advisories/GHSA-3rfq-4wpf-qqw3>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-44242>
- <https://github.com/micronaut-projects/micronaut-core>
- <https://github.com/micronaut-projects/micronaut-core/releases/tag/v3.10.6>
- <https://github.com/micronaut-projects/micronaut-core/releases/tag/v3.8.14>
- <https://github.com/micronaut-projects/micronaut-core/releases/tag/v4.10.22>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-3rfq-4wpf-qqw3>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-3rfq-4wpf-qqw3/>. Everything for agents: <https://agentprime.io/llms.txt>.