# CVE-2025-56221: Auth bypass in n/a

> Attackers can bypass authentication via brute force due to missing rate limiting in the login mechanism.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Oct 2025
- **Updated:** 17 Oct 2025
- **Also known as:** GHSA-w54h-jpcf-gvh9

## What is CVE-2025-56221?

CVE-2025-56221 is a critical authentication bypass vulnerability in n/a, published on 17 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A lack of rate limiting in the login mechanism of SigningHub v8.6.8 allows attackers to bypass authentication via a brute force attack.

Weakness: CWE-307 (Improper Restriction of Excessive Authentication Attempts)

## Which versions are affected by CVE-2025-56221?

It affects 1 product.


Products: Ascertia Signinghub.

## How do I fix CVE-2025-56221?

No fix has been published for CVE-2025-56221 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-56221 being exploited?

There is no known exploitation of CVE-2025-56221 in the wild and no public exploit code.

Public exploit code:

- https://github.com/saykino/CVE-2025-56221 (github_poc): https://github.com/saykino/CVE-2025-56221

## Other vulnerabilities in n/a

- [CVE-2025-54321](https://insights.sbomify.com/CVE-2025-54321/): Denial of service in n/a (critical 9.8)
- [CVE-2025-56218](https://insights.sbomify.com/CVE-2025-56218/): File upload in n/a (critical 9.8)
- [CVE-2025-56224](https://insights.sbomify.com/CVE-2025-56224/): Security feature bypass in n/a (high 8.1)
- [CVE-2025-56223](https://insights.sbomify.com/CVE-2025-56223/): Denial of service in n/a (high 7.5)
- [CVE-2025-56219](https://insights.sbomify.com/CVE-2025-56219/): Missing authorization in n/a (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-56221 and fix it if it is affected.

What it is: CVE-2025-56221 is a critical authentication bypass vulnerability in n/a, published on 17 Oct 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-2025-56221 in the wild and no public exploit code.

Affected product: n/a. 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-2025-56221/ (Markdown: https://insights.sbomify.com/CVE-2025-56221/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-56221
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-56221
- OSV: https://osv.dev/vulnerability/CVE-2025-56221

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-56221/
Summaries are generated and may contain mistakes; the official description above is the record.