# CVE-2026-96423: Heap-based Buffer Overflow in Wireshark

> A heap-based buffer overflow in the X11 protocol dissector allows attackers to cause a denial of service in Wireshark.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **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:** Yes
- **Published:** 29 Sep 2026
- **Updated:** 14 Oct 2026
- **Also known as:** AZL-105003, DEBIAN-CVE-2026-96423, GHSA-969r-pwxc-fjq2, MINI-p8xc-c3x3-frwp, UBUNTU-CVE-2026-96423

## What is CVE-2026-96423?

CVE-2026-96423 is a medium-severity memory corruption vulnerability in Wireshark Wireshark, published on 29 Sep 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

X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service

Weakness: CWE-125 (Out-of-bounds Read), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-96423?

It affects 1 product.


Products: Wireshark Wireshark.

## How do I fix CVE-2026-96423?

Upgrade to a fixed version.

## Is CVE-2026-96423 being exploited?

There is no known exploitation of CVE-2026-96423 in the wild and no public exploit code.

## Other vulnerabilities in Wireshark Wireshark

- [CVE-2011-0444](https://insights.sbomify.com/CVE-2011-0444/): Memory corruption in n/a (critical 10.0)
- [CVE-2010-2994](https://insights.sbomify.com/CVE-2010-2994/): Memory corruption in n/a (critical 10.0)
- [CVE-2010-2995](https://insights.sbomify.com/CVE-2010-2995/): Memory corruption in n/a (critical 10.0)
- [CVE-2009-1266](https://insights.sbomify.com/CVE-2009-1266/): Other in n/a (critical 10.0)
- [CVE-2009-1210](https://insights.sbomify.com/CVE-2009-1210/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-96423 and fix it if it is affected.

What it is: CVE-2026-96423 is a medium-severity memory corruption vulnerability in Wireshark Wireshark, published on 29 Sep 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-2026-96423 in the wild and no public exploit code.

Affected product: Wireshark Wireshark. 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-2026-96423/ (Markdown: https://insights.sbomify.com/CVE-2026-96423/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-96423
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96423
- OSV: https://osv.dev/vulnerability/CVE-2026-96423

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-96423/
Summaries are generated and may contain mistakes; the official description above is the record.