Prototype Pollution Vulnerability in expr-eval Package by npm
CVE-2025-13204

7.3HIGH

Key Information:

Vendor

Silentmatt

Status
Expr-eval
Vendor
CVE Published:
14 November 2025

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2025-13204?

The expr-eval package, commonly used in npm environments, is vulnerable to a prototype pollution attack. An attacker with access to the express eval interface can manipulate the JavaScript prototype chain, potentially resulting in arbitrary code execution. To mitigate this risk, it is recommended to migrate to the expr-eval-fork package, which addresses this security concern.

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Deploy the Patch

Affected Version(s)

expr-eval 0 <= 2.0.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2025-13204 - Proof of Concept

References

https://www.npmjs.com/package/expr-eval-fork
https://github.com/silentmatt/expr-eval
https://github.com/jorenbroekema/expr-eval

CVSS V3.1

Score:
7.3
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

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