# CVE-2025-5241: Denial-of-Service Vulnerability in MELSEC iQ-F Series

> Remote attackers can lock out legitimate users from Mitsubishi MELSEC iQ-F PLCs by triggering the account lockout mechanism with repeated failed login attempts.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jul 2025
- **Updated:** 11 Jul 2025
- **Also known as:** GHSA-7w8q-8495-mwhj

## What is CVE-2025-5241?

CVE-2025-5241 is a medium-severity denial of service vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-CCLGN-MS, published on 11 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Overly Restrictive Account Lockout Mechanism vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series allows a remote unauthenticated attacker to lockout legitimate users for a certain period by repeatedly attempting to login with incorrect passwords. The legitimate users will be unable to login until a certain period has passed after the lockout or until the product is reset.

Weakness: CWE-645 (Overly Restrictive Account Lockout Mechanism)

## Which versions are affected by CVE-2025-5241?


## How do I fix CVE-2025-5241?

No fix has been published for CVE-2025-5241 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-5241 being exploited?

There is no known exploitation of CVE-2025-5241 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-5241 and fix it if it is affected.

What it is: CVE-2025-5241 is a medium-severity denial of service vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-CCLGN-MS, published on 11 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-5241 in the wild and no public exploit code.

Affected product: Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-CCLGN-MS. 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-2025-5241/ (Markdown: https://insights.sbomify.com/CVE-2025-5241/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-5241
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-5241
- OSV: https://osv.dev/vulnerability/CVE-2025-5241

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-5241/
Summaries are generated and may contain mistakes; the official description above is the record.