# CVE-2026-86926: Memory corruption in FileMaker Server

> A heap buffer overflow in FileMaker Server allows arbitrary code execution via a malicious database file, requiring an upgrade to the latest version.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/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:** No
- **Published:** 23 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-9vrp-wjh8-mfg5

## What is CVE-2026-86926?

CVE-2026-86926 is a high-severity memory corruption vulnerability in Claris FileMaker Server, published on 23 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

A heap buffer overflow vulnerability in the FileMaker Server database engine block parsing routine allowed a maliciously crafted .fmp12 database file to cause memory corruption, potentially leading to arbitrary code execution. This vulnerability is addressed in FileMaker Server version 26.0.3.

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

## Which versions are affected by CVE-2026-86926?

It affects 1 product.


Products: Claris Filemaker Server.

## How do I fix CVE-2026-86926?

No fix has been published for CVE-2026-86926 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86926 being exploited?

There is no known exploitation of CVE-2026-86926 in the wild and no public exploit code.

## Other vulnerabilities in Claris FileMaker Server

- [CVE-2025-46295](https://insights.sbomify.com/CVE-2025-46295/): Code injection in FileMaker Server (critical 9.8)
- [CVE-2026-86930](https://insights.sbomify.com/CVE-2026-86930/): Information disclosure in FileMaker Server (critical 9.1)
- [CVE-2026-86934](https://insights.sbomify.com/CVE-2026-86934/): Auth bypass in FileMaker Server (critical 9.1)
- [CVE-2024-27790](https://insights.sbomify.com/CVE-2024-27790/): Missing authorization in FileMaker Server (high 7.5)
- [CVE-2025-46320](https://insights.sbomify.com/CVE-2025-46320/): Cross-site scripting in FileMaker Server (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86926 and fix it if it is affected.

What it is: CVE-2026-86926 is a high-severity memory corruption vulnerability in Claris FileMaker Server, published on 23 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-2026-86926 in the wild and no public exploit code.

Affected product: Claris FileMaker Server. 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-2026-86926/ (Markdown: https://insights.sbomify.com/CVE-2026-86926/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86926
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86926
- OSV: https://osv.dev/vulnerability/CVE-2026-86926

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86926/
Summaries are generated and may contain mistakes; the official description above is the record.