# CVE-2026-33012: Micronaut Framework vulnerable to a Denial of Service in HTML error response caching

> Remote attackers can cause denial of service via unbounded heap growth in Micronaut Framework's HTML error response caching mechanism.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Mar 2026
- **Updated:** 20 Mar 2026
- **Also known as:** GHSA-2hcp-gjrf-7fhc, MINI-wmvw-6pwf-gvh6

## What is CVE-2026-33012?

CVE-2026-33012 is a high-severity denial of service vulnerability in micronaut-projects micronaut-core, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Micronaut Framework is a JVM-based full stack Java framework designed for building modular, easily testable JVM applications.  Versions 4.7.0 through 4.10.16 used an unbounded ConcurrentHashMap cache with no eviction policy in its DefaultHtmlErrorResponseBodyProvider. If the application throws an exception whose message may be influenced by an attacker, (for example, including request query value parameters) it could be used by remote attackers to cause an unbounded heap growth and OutOfMemoryError, leading to DoS. This issue has been fixed in version 4.10.7.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-33012?

2 open source packages ship an affected version, including io.micronaut:micronaut-http-server. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.micronaut:micronaut-http-server` | Maven | From 4.7.0 | 4.10.17 |
| `io.micronaut:micronaut-http-server` | Maven | From 4.7.0 | 4.10.17 |

Products: Objectcomputing Micronaut.

## How do I fix CVE-2026-33012?

Upgrade io.micronaut:micronaut-http-server to 4.10.17 or later.

## Is CVE-2026-33012 being exploited?

There is no known exploitation of CVE-2026-33012 in the wild and no public exploit code.

## Other vulnerabilities in micronaut-projects micronaut-core

- [CVE-2020-7611](https://insights.sbomify.com/CVE-2020-7611/): Micronaut's HTTP client is vulnerable to HTTP Request Header Injection (critical 9.8)
- [CVE-2026-33013](https://insights.sbomify.com/CVE-2026-33013/): Micronaut vulnerable to DoS via crafted form-urlencoded body binding with descending array indices (high 8.2)
- [CVE-2021-32769](https://insights.sbomify.com/CVE-2021-32769/): Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in micronaut-core (high 7.5)
- [CVE-2022-21700](https://insights.sbomify.com/CVE-2022-21700/): Memory leak in micronaut-core (medium 5.3)
- [CVE-2024-23639](https://insights.sbomify.com/CVE-2024-23639/): micronaut-core management endpoints vulnerable to drive-by localhost attack (medium 5.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33012 and fix it if it is affected.

What it is: CVE-2026-33012 is a high-severity denial of service vulnerability in micronaut-projects micronaut-core, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33012 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.micronaut:micronaut-http-server (Maven): affected from 4.7.0; fixed in 4.10.17
- io.micronaut:micronaut-http-server (Maven): affected from 4.7.0; fixed in 4.10.17

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33012/ (Markdown: https://insights.sbomify.com/CVE-2026-33012/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33012
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33012
- OSV: https://osv.dev/vulnerability/CVE-2026-33012

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-33012/
Summaries are generated and may contain mistakes; the official description above is the record.