# CVE-2026-22035: Greenshot Vulnerable to OS Command Injection via ExternalCommand Plugin

> Attackers can execute arbitrary OS commands via malicious filenames in Greenshot's ExternalCommand plugin due to unsanitized input processing.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/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:** 8 Jan 2026
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-7hvw-q8q5-gpmj

## What is CVE-2026-22035?

CVE-2026-22035 is a high-severity command injection vulnerability in greenshot, published on 8 Jan 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

Greenshot is an open source Windows screenshot utility. Versions 1.3.310 and below arvulnerable to OS Command Injection through unsanitized filename processing. The FormatArguments method in ExternalCommandDestination.cs:269 uses string.Format() to insert user-controlled filenames directly into shell commands without sanitization, allowing attackers to execute arbitrary commands by crafting malicious filenames containing shell metacharacters. This issue is fixed in version 1.3.311.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-22035?

It affects 1 product.


Products: Getgreenshot Greenshot.

## How do I fix CVE-2026-22035?

No fix has been published for CVE-2026-22035 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-22035 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22035 exists.

## Other vulnerabilities in greenshot

- [CVE-2025-59050](https://insights.sbomify.com/CVE-2025-59050/): Greenshot — Insecure .NET deserialization via WM_COPYDATA enables local code execution (high 8.4)
- [CVE-2023-34634](https://insights.sbomify.com/CVE-2023-34634/): Deserialization in n/a (high 7.8)
- [CVE-2026-25792](https://insights.sbomify.com/CVE-2026-25792/): Greenshot Vulnerable to OS Command Injection via ExternalCommand Plugin (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-22035 and fix it if it is affected.

What it is: CVE-2026-22035 is a high-severity command injection vulnerability in greenshot, published on 8 Jan 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22035 exists.

Affected product: greenshot. 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-2026-22035/ (Markdown: https://insights.sbomify.com/CVE-2026-22035/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22035
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22035
- OSV: https://osv.dev/vulnerability/CVE-2026-22035

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-22035/
Summaries are generated and may contain mistakes; the official description above is the record.