# CVE-2026-45698: Netatalk has Integer Underflow → Stack Buffer Overflow in deletedir()

> An integer underflow in Netatalk's afpd daemon leads to a stack buffer overflow, allowing remote attackers to execute arbitrary code via crafted filenames.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-45698, GHSA-5443-v9xg-mqgv, UBUNTU-CVE-2026-45698

## What is CVE-2026-45698?

CVE-2026-45698 is a high-severity vulnerability in netatalk, published on 17 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a stack-based buffer overflow exists in the deletedir() function of Netatalk's afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. deletedir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library's renameat() cannot handle. The function attempts to prevent buffer overflows by tracking available space in a size_t remain variable. However, the arithmetic used to compute remain results in an unsigned integer underflow, causing the variable to become SIZE_MAX. Because of this, the subsequent boundary check always evaluates as safe, allowing an unbounded strcpy() operation to copy attacker-controlled filenames into a nearly full stack buffer. Version 4.4.3 patches the issue.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2026-45698?


## How do I fix CVE-2026-45698?

Upgrade to a fixed version.

## Is CVE-2026-45698 being exploited?

There is no known exploitation of CVE-2026-45698 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45698 and fix it if it is affected.

What it is: CVE-2026-45698 is a high-severity vulnerability in netatalk, published on 17 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45698 in the wild and no public exploit code.

Affected product: netatalk. 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-2026-45698/ (Markdown: https://insights.sbomify.com/CVE-2026-45698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45698
- OSV: https://osv.dev/vulnerability/CVE-2026-45698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45698/
Summaries are generated and may contain mistakes; the official description above is the record.