# CVE-2023-53959: FileZilla Client 3.63.1 DLL Hijacking via Missing TextShaping.dll

> Attackers can execute arbitrary code by placing a malicious DLL in the application directory, leading to remote code execution upon launch.

- **Severity:** High 8.5 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Dec 2025
- **Updated:** 7 Apr 2026
- **Also known as:** GHSA-4h23-hj4v-f4xg, UBUNTU-CVE-2023-53959

## What is CVE-2023-53959?

CVE-2023-53959 is a high-severity code injection vulnerability in filezilla-project FileZilla Client, published on 19 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

FileZilla Client 3.63.1 contains a DLL hijacking vulnerability that allows attackers to execute malicious code by placing a crafted TextShaping.dll in the application directory. Attackers can generate a reverse shell payload using msfvenom and replace the missing DLL to achieve remote code execution when the application launches.

Weakness: CWE-427 (Uncontrolled Search Path Element)

## Which versions are affected by CVE-2023-53959?

It affects 1 product.


Products: Filezilla-Project Filezilla Client.

## How do I fix CVE-2023-53959?

No fix has been published for CVE-2023-53959 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-53959 being exploited?

There is no known exploitation of CVE-2023-53959 in the wild and no public exploit code.

## Other vulnerabilities in filezilla-project FileZilla Client

- [CVE-2019-25683](https://insights.sbomify.com/CVE-2019-25683/): FileZilla 3.40.0 Denial of Service via Local Search (medium 6.9)
- [CVE-2022-29620](https://insights.sbomify.com/CVE-2022-29620/): Information disclosure in n/a (medium 6.5)
- [CVE-2016-15003](https://insights.sbomify.com/CVE-2016-15003/): FileZilla Client Installer uninstall.exe unquoted search path (medium 6.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53959 and fix it if it is affected.

What it is: CVE-2023-53959 is a high-severity code injection vulnerability in filezilla-project FileZilla Client, published on 19 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-53959 in the wild and no public exploit code.

Affected product: filezilla-project FileZilla Client. 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-2023-53959/ (Markdown: https://insights.sbomify.com/CVE-2023-53959/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53959
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53959
- OSV: https://osv.dev/vulnerability/CVE-2023-53959

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From sbomify Insights: https://insights.sbomify.com/CVE-2023-53959/
Summaries are generated and may contain mistakes; the official description above is the record.