# CVE-2025-57351: ts-fns has prototype pollution vulnerability

> Attackers can inject properties into the global prototype via the assign function, potentially causing crashes, unexpected code execution, or security bypasses.

- **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-g7wq-wggw-vmhg

## What is CVE-2025-57351?

CVE-2025-57351 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 prototype pollution vulnerability exists in the ts-fns package versions prior to 13.0.7, where insufficient validation of user-provided keys in the assign function allows attackers to manipulate the Object.prototype chain. By leveraging this flaw, adversaries may inject arbitrary properties into the global object's prototype, potentially leading to application crashes, unexpected code execution behaviors, or bypasses of security-critical validation logic dependent on prototype integrity. The vulnerability stems from improper handling of deep property assignment operations within the library's public API functions. This issue remains unaddressed in the latest available version.

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

## Which versions are affected by CVE-2025-57351?

2 open source packages ship an affected version, including ts-fns.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ts-fns` | npm | All versions to 13.1.3 | None |
| `ts-fns` | npm | All versions to 13.1.3 | None |

## How do I fix CVE-2025-57351?

No fix has been published for CVE-2025-57351 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-57351 being exploited?

There is no known exploitation of CVE-2025-57351 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-57351 and fix it if it is affected.

What it is: CVE-2025-57351 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-2025-57351 in the wild and no public exploit code.

Affected packages and fixed versions:
- ts-fns (npm): affected all versions up to 13.1.3; no fix listed
- ts-fns (npm): affected all versions up to 13.1.3; 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-2025-57351/ (Markdown: https://insights.sbomify.com/CVE-2025-57351/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-57351
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-57351
- OSV: https://osv.dev/vulnerability/CVE-2025-57351

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-57351/
Summaries are generated and may contain mistakes; the official description above is the record.