# OSV-2024-567: Security exception in jflex.core.NFA.insertNFA

> A security exception in the JFlex library can cause a denial of service when processing specific inputs.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Not stated
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Jun 2024

## What is OSV-2024-567?

OSV-2024-567 is a denial of service vulnerability in jflex, published on 16 Jun 2024. 

### Official description

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=69587

```
Crash type: Security exception
Crash state:
jflex.core.NFA.insertNFA
jflex.core.unicode.IntCharSet.indexOf
jflex.core.unicode.IntCharSet.contains
```

## Which versions are affected by OSV-2024-567?

1 open source package ship an affected version, including jflex.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `jflex` | OSS-Fuzz | All versions | None |

## How do I fix OSV-2024-567?

No fix has been published for OSV-2024-567 yet. Limit exposure of the affected software until one is available.

## Is OSV-2024-567 being exploited?

There is no known exploitation of OSV-2024-567 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for OSV-2024-567 and fix it if it is affected.

What it is: OSV-2024-567 is a denial of service vulnerability in jflex, published on 16 Jun 2024. 
Exploitation: There is no known exploitation of OSV-2024-567 in the wild and no public exploit code.

Affected packages and fixed versions:
- jflex (OSS-Fuzz): affected all versions; no fix listed

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/OSV-2024-567/ (Markdown: https://insights.sbomify.com/OSV-2024-567/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/OSV-2024-567

---
From sbomify Insights: https://insights.sbomify.com/OSV-2024-567/
Summaries are generated and may contain mistakes; the official description above is the record.