# CVE-2025-57354: counterpart vulnerable to prototype pollution

> Prototype pollution in the counterpart library allows attackers to inject properties into the Object prototype, potentially leading to remote code execution or denial of service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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:** 24 Sep 2025
- **Updated:** 25 Sep 2025
- **Also known as:** GHSA-2488-w585-72ch

## What is CVE-2025-57354?

CVE-2025-57354 is a medium-severity code injection 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

A vulnerability exists in the 'counterpart' library for Node.js and the browser due to insufficient sanitization of user-controlled input in translation key processing. The affected versions prior to 0.18.6 allow attackers to manipulate the library's translation functionality by supplying maliciously crafted keys containing prototype chain elements (e.g., __proto__ ), leading to prototype pollution. This weakness enables adversaries to inject arbitrary properties into the JavaScript Object prototype through the first parameter of the translate method when combined with specific separator configurations, potentially resulting in denial-of-service conditions or remote code execution in vulnerable applications. The issue arises from the library's failure to properly validate or neutralize special characters in translation key inputs before processing.

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

## Which versions are affected by CVE-2025-57354?

2 open source packages ship an affected version, including counterpart.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `counterpart` | npm | All versions to 0.18.6 | None |
| `counterpart` | npm | All versions to 0.18.6 | None |

## How do I fix CVE-2025-57354?

No fix has been published for CVE-2025-57354 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-57354 being exploited?

There is no known exploitation of CVE-2025-57354 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-57354 and fix it if it is affected.

What it is: CVE-2025-57354 is a medium-severity code injection 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: There is no known exploitation of CVE-2025-57354 in the wild and no public exploit code.

Affected packages and fixed versions:
- counterpart (npm): affected all versions up to 0.18.6; no fix listed
- counterpart (npm): affected all versions up to 0.18.6; 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-2025-57354/ (Markdown: https://insights.sbomify.com/CVE-2025-57354/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-57354
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-57354
- OSV: https://osv.dev/vulnerability/CVE-2025-57354

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-57354/
Summaries are generated and may contain mistakes; the official description above is the record.