# CVE-2020-36565: Directory traversal on Windows in github.com/labstack/echo/v4

> An attacker can read arbitrary files outside the intended directory on Windows systems using the Echo web framework's static file handler.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Dec 2022
- **Updated:** 23 Apr 2025
- **Also known as:** GHSA-j453-hm5x-c46w, GO-2021-0051, UBUNTU-CVE-2020-36565

## What is CVE-2020-36565?

CVE-2020-36565 is a medium-severity path traversal vulnerability in github.com/labstack/echo/v4, published on 7 Dec 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Due to improper sanitization of user input on Windows, the static file handler allows for directory traversal, allowing an attacker to read files outside of the target directory that the server has permission to read.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2020-36565?

3 open source packages ship an affected version, including github.com/labstack/echo/v4. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/labstack/echo/v4` | Go | All versions | 4.1.18-0.20201215153152-4422e3b66b9f |
| `github.com/labstack/echo/v4` | Go | All versions | 4.2.0 |
| `github.com/labstack/echo/v4` | Go | All versions | 4.2.0 |

Products: Labstack Echo.

## How do I fix CVE-2020-36565?

Upgrade github.com/labstack/echo/v4 to a fixed version for your release line: 4.1.18-0.20201215153152-4422e3b66b9f or 4.2.0.

## Is CVE-2020-36565 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-36565 exists.

## Other vulnerabilities in github.com/labstack/echo/v4

- [CVE-2022-40083](https://insights.sbomify.com/CVE-2022-40083/): Labstack Echo Open Redirect vulnerability (critical 9.6)
- [CVE-2026-25766](https://insights.sbomify.com/CVE-2026-25766/): Echo has a Windows path traversal via backslash in middleware.Static default filesystem (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-36565 and fix it if it is affected.

What it is: CVE-2020-36565 is a medium-severity path traversal vulnerability in github.com/labstack/echo/v4, published on 7 Dec 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-36565 exists.

Affected packages and fixed versions:
- github.com/labstack/echo/v4 (Go): affected all versions; fixed in 4.1.18-0.20201215153152-4422e3b66b9f
- github.com/labstack/echo/v4 (Go): affected all versions; fixed in 4.2.0
- github.com/labstack/echo/v4 (Go): affected all versions; fixed in 4.2.0

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-2020-36565/ (Markdown: https://insights.sbomify.com/CVE-2020-36565/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36565
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36565
- OSV: https://osv.dev/vulnerability/CVE-2020-36565

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-36565/
Summaries are generated and may contain mistakes; the official description above is the record.