# CVE-2026-16440: Denial of service in Eclipse OpenJ9

> Attackers can cause a segmentation fault and crash the application by providing a crafted class file with deeply nested annotations.

- **Severity:** Medium 5.7 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 19 Aug 2026
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-ch6r-v7rg-4jqx, GHSA-jxfm-5353-qwhv

## What is CVE-2026-16440?

CVE-2026-16440 is a medium-severity denial of service vulnerability in Eclipse OpenJ9, published on 19 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

In Eclipse OpenJ9 versions up to 0.60, a crafted .class file with deeply nested annotations causes a segmentation fault.

Weakness: CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2026-16440?


## How do I fix CVE-2026-16440?

Upgrade to a fixed version.

## Is CVE-2026-16440 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-16440 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16440 and fix it if it is affected.

What it is: CVE-2026-16440 is a medium-severity denial of service vulnerability in Eclipse OpenJ9, published on 19 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-16440 exists.

Affected product: Eclipse OpenJ9. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-16440/ (Markdown: https://insights.sbomify.com/CVE-2026-16440/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16440
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16440
- OSV: https://osv.dev/vulnerability/CVE-2026-16440

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-16440/
Summaries are generated and may contain mistakes; the official description above is the record.