# CVE-2017-20227: JAD 1.5.8e-1kali1 Stack-Based Buffer Overflow

> Attackers can execute arbitrary code by providing overly long input to the JAD Java Decompiler, causing a stack-based buffer overflow.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Mar 2026
- **Updated:** 1 Apr 2026
- **Also known as:** GHSA-qfhh-979f-m8jg

## What is CVE-2017-20227?

CVE-2017-20227 is a critical memory corruption vulnerability in Varaneckas JAD Java Decompiler, published on 28 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

JAD Java Decompiler 1.5.8e-1kali1 and prior contains a stack-based buffer overflow vulnerability that allows attackers to execute arbitrary code by supplying overly long input that exceeds buffer boundaries. Attackers can craft malicious input passed to the jad command to overflow the stack and execute a return-oriented programming chain that spawns a shell.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2017-20227?

It affects 1 product.


Products: Varaneckas Jad Java Decompiler.

## How do I fix CVE-2017-20227?

No fix has been published for CVE-2017-20227 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-20227 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-20227 exists.

## Other vulnerabilities in Varaneckas JAD Java Decompiler

- [CVE-2016-20049](https://insights.sbomify.com/CVE-2016-20049/): JAD 1.5.8e-1kali1 Stack-Based Buffer Overflow Remote Code Execution (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-20227 and fix it if it is affected.

What it is: CVE-2017-20227 is a critical memory corruption vulnerability in Varaneckas JAD Java Decompiler, published on 28 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-20227 exists.

Affected product: Varaneckas JAD Java Decompiler. 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-2017-20227/ (Markdown: https://insights.sbomify.com/CVE-2017-20227/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-20227
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-20227
- OSV: https://osv.dev/vulnerability/CVE-2017-20227

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-20227/
Summaries are generated and may contain mistakes; the official description above is the record.