# CVE-2025-54135: Cursor Agent is vulnerable to prompt injection via MCP Special Files

> Attackers can achieve remote code execution by exploiting prompt injection to write malicious MCP configuration files without user approval.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/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:** No
- **Published:** 5 Aug 2025
- **Updated:** 5 Aug 2025

## What is CVE-2025-54135?

CVE-2025-54135 is a high-severity code injection vulnerability in cursor, published on 5 Aug 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Cursor is a code editor built for programming with AI. Cursor allows writing in-workspace files with no user approval in versions below 1.3.9, If the file is a dotfile, editing it requires approval but creating a new one doesn't. Hence, if sensitive MCP files, such as the .cursor/mcp.json file don't already exist in the workspace, an attacker can chain a indirect prompt injection vulnerability to hijack the context to write to the settings file and trigger RCE on the victim without user approval. This is fixed in version 1.3.9.

Weakness: CWE-829 (Inclusion of Functionality from Untrusted Control Sphere), CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2025-54135?

It affects 1 product.


Products: Anysphere Cursor.

## How do I fix CVE-2025-54135?

No fix has been published for CVE-2025-54135 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-54135 being exploited?

There is no known exploitation of CVE-2025-54135 in the wild and no public exploit code.

Public exploit code:

- https://github.com/anntsmart/CVE-2025-54135 (github_poc): https://github.com/anntsmart/CVE-2025-54135
- A repo for CVE-2025-54135 reproduction (github_poc): https://github.com/hn1e13/test-mcp

## Other vulnerabilities in cursor

- [CVE-2026-50548](https://insights.sbomify.com/CVE-2026-50548/): Cursor Desktop sandbox escape via agent-controlled working directory (critical 9.3)
- [CVE-2026-50549](https://insights.sbomify.com/CVE-2026-50549/): Cursor Desktop sandbox escape via symlink and failed path canonicalization (critical 9.3)
- [CVE-2025-64106](https://insights.sbomify.com/CVE-2025-64106/): Cursor: Speedbump Modal Bypass in MCP Server Deep-Link (high 8.8)
- [CVE-2025-64107](https://insights.sbomify.com/CVE-2025-64107/): Cursor is Vulnerable to Path Manipulation Using Backslashes on Windows (high 8.8)
- [CVE-2025-64108](https://insights.sbomify.com/CVE-2025-64108/): Cursor's Sensitive File Modification can Lead to NTFS Path Quirks (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-54135 and fix it if it is affected.

What it is: CVE-2025-54135 is a high-severity code injection vulnerability in cursor, published on 5 Aug 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-54135 in the wild and no public exploit code.

Affected product: cursor. 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-2025-54135/ (Markdown: https://insights.sbomify.com/CVE-2025-54135/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-54135
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-54135
- OSV: https://osv.dev/vulnerability/CVE-2025-54135

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-54135/
Summaries are generated and may contain mistakes; the official description above is the record.