# CVE-2025-57323: mpregular vulnerable to prototype pollution

> Attackers can cause denial of service via prototype pollution in the mpregular JavaScript framework by injecting properties into Object.prototype.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 24 Sep 2025
- **Updated:** 24 Sep 2025
- **Also known as:** GHSA-xx4g-r65p-3qf2

## What is CVE-2025-57323?

CVE-2025-57323 is a high-severity vulnerability in n/a, published on 24 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

mpregular is a package that provides a small program development framework based on RegularJS. A Prototype Pollution vulnerability in the mp.addEventHandler function of mpregular version 0.2.0 and before allows attackers to inject properties on Object.prototype via supplying a crafted payload, causing denial of service (DoS) as the minimum consequence.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes)

## Which versions are affected by CVE-2025-57323?

2 open source packages ship an affected version, including mpregular. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mpregular` | npm | All versions to 0.2.0 | None |
| `mpregular` | npm | All versions to 0.2.0 | None |

Products: Regularjs Mpregular.

## How do I fix CVE-2025-57323?

No fix has been published for CVE-2025-57323 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-57323 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-57323 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-57323 and fix it if it is affected.

What it is: CVE-2025-57323 is a high-severity vulnerability in n/a, published on 24 Sep 2025. 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-2025-57323 exists.

Affected packages and fixed versions:
- mpregular (npm): affected all versions up to 0.2.0; no fix listed
- mpregular (npm): affected all versions up to 0.2.0; no fix listed

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-2025-57323/ (Markdown: https://insights.sbomify.com/CVE-2025-57323/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-57323
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-57323
- OSV: https://osv.dev/vulnerability/CVE-2025-57323

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-57323/
Summaries are generated and may contain mistakes; the official description above is the record.