# CVE-2026-8484: Heap buffer overflow in Jansi

> Heap buffer overflow in Jansi JNI wrapper allows attackers to cause application crashes via denial of service.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 16 Jun 2026
- **Updated:** 16 Jun 2026
- **Also known as:** AZL-90095, DEBIAN-CVE-2026-8484, GHSA-fh45-7f3j-r575, UBUNTU-CVE-2026-8484

## What is CVE-2026-8484?

CVE-2026-8484 is a medium-severity memory corruption vulnerability in FuseSource jansi, published on 16 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A heap buffer overflow vulnerability exists in the Jansi JNI "ioctl()" wrapper due to a lack of size verification for the argument array before the system call. This can lead to heap corruption and application crashes (DoS).
All versions are believed to be vulnerable. This project is unmaintained at the time of CVE assignment.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-8484?


## How do I fix CVE-2026-8484?

No fix has been published for CVE-2026-8484 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8484 being exploited?

There is no known exploitation of CVE-2026-8484 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8484 and fix it if it is affected.

What it is: CVE-2026-8484 is a medium-severity memory corruption vulnerability in FuseSource jansi, published on 16 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-8484 in the wild and no public exploit code.

Affected product: FuseSource jansi. 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-2026-8484/ (Markdown: https://insights.sbomify.com/CVE-2026-8484/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8484
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8484
- OSV: https://osv.dev/vulnerability/CVE-2026-8484

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8484/
Summaries are generated and may contain mistakes; the official description above is the record.