# CVE-2026-5404: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') in Wireshark

> A buffer overflow in the K12 RF5 file parser allows attackers to cause a denial of service in Wireshark.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/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:** 30 Apr 2026
- **Updated:** 1 May 2026
- **Also known as:** AZL-85328, DEBIAN-CVE-2026-5404, GHSA-8rgp-w6w3-2537, UBUNTU-CVE-2026-5404

## What is CVE-2026-5404?

CVE-2026-5404 is a medium-severity memory corruption vulnerability in Wireshark Wireshark, published on 30 Apr 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

K12 RF5 file parser crash in Wireshark 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14 allows denial of service

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2026-5404?

It affects 1 product.


Products: Wireshark Wireshark.

## How do I fix CVE-2026-5404?

Upgrade to a fixed version.

## Is CVE-2026-5404 being exploited?

There is no known exploitation of CVE-2026-5404 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-2026-5404 and fix it if it is affected.

What it is: CVE-2026-5404 is a medium-severity memory corruption vulnerability in Wireshark Wireshark, published on 30 Apr 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-2026-5404 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-2026-5404/ (Markdown: https://insights.sbomify.com/CVE-2026-5404/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5404
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5404
- OSV: https://osv.dev/vulnerability/CVE-2026-5404

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5404/
Summaries are generated and may contain mistakes; the official description above is the record.