CVE-2025-13204: Expr eval Expr-eval Vulnerable To Prototype Pollution Vulnerability

HIGH
Advisory Identifier: GHSA-8gw3-rxh4-v6jx
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CVSS 7.3
CWE-1321
Published
Advisory Summary

CVE-2025-13204 is a HIGH (CVSS 7.3) expr-eval vulnerable to prototype pollution vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Expr eval libraries in the npm ecosystem. The issue involves expr-eval vulnerable to prototype pollution. Remediation is available by upgrading affected packages to version 2.0.2.

CVE-2025-13204 at a Glance

CVE Identifier CVE-2025-13204
GHSA Identifier GHSA-8gw3-rxh4-v6jx
Severity HIGH
CVSS v3.1 Base Score 7.3
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Expr eval
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2025-13204

To remediate this vulnerability, upgrade all affected Expr eval dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

expr-eval fixed: Latest secure release 
npm install expr-eval@Latest secure release
expr-eval-fork fixed: 2.0.2 
npm install expr-eval-fork@2.0.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls expr-eval

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2025-13204, inspect your project dependencies using npm:

npm ls expr-eval

Analyze the terminal output to locate any version of Expr eval in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.0.2), your application is affected.

Note: The npm ls expr-eval command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), where the product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. In Expr eval, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

npm package `expr-eval` is vulnerable to Prototype Pollution. An attacker with access to express eval interface can use JavaScript prototype-based inheritance model to achieve arbitrary code execution. The npm expr-eval-fork package resolves this issue.

CVE-2025-13204 Affected Expr eval Versions

2 component(s)
Fixed Versions:
2.0.2
Product / Package Ecosystem Affected Versions Fixed Version
expr-eval
npm/expr-eval
npm
≤ 2.0.2
expr-eval-fork
npm/expr-eval-fork
npm
< 2.0.2
2.0.2

References

NVD — CVE-2025-13204 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-13204
Expr eval Source Repository REPOSITORY
https://github.com/silentmatt/expr-eval/pull/252/files
Security Fix Commit FIX COMMIT
https://github.com/jorenbroekema/expr-eval/commit/6c475a118643ae0efe012de283e932fb8b74324b
Security Fix Commit FIX COMMIT
https://github.com/silentmatt/expr-eval/commit/6e889e0e75c50ac37d70c35388602025650e0c50
Expr eval Source Repository REPOSITORY
https://github.com/SECCON/SECCON2022_final_CTF/blob/main/jeopardy/web/babybox/solver/solver.py
Expr eval Source Repository REPOSITORY
https://github.com/jorenbroekema/expr-eval
Expr eval Source Repository REPOSITORY
https://github.com/silentmatt/expr-eval
Expr eval Source Repository REPOSITORY
https://github.com/vladko312/extras/blob/f549d505af300fd74a01b46fab2102990ff1c14d/expr-eval.py
www.huntr.dev/bounties/1-npm-expr... WEB
https://www.huntr.dev/bounties/1-npm-expr-eval
www.npmjs.com/package/expr-eval-f... WEB
https://www.npmjs.com/package/expr-eval-fork

Frequently Asked Questions

What is CVE-2025-13204?
CVE-2025-13204 is a security vulnerability in Expr eval involving expr-eval vulnerable to Prototype Pollution under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Expr eval versions are affected?
Affected versions include releases prior to 2.0.2 across affected packages: expr-eval, expr-eval-fork.
What version fixes CVE-2025-13204?
Upgrading to 2.0.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is expr-eval affected?
Yes, expr-eval is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
Is expr-eval-fork affected?
Yes, expr-eval-fork is affected in releases prior to 2.0.2. Upgrade your dependency to 2.0.2 or later.
What is the CVSS score of CVE-2025-13204?
CVE-2025-13204 has a CVSS v3.1 base score of 7.3 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
What CWE is associated with CVE-2025-13204?
CVE-2025-13204 is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.).
How can I check npm dependencies for CVE-2025-13204?
Run the dependency tree command: 'npm ls expr-eval'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
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  "database_specific" : {
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    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-11-17T18:39:19Z",
    "nvd_published_at" : "2025-11-14T17:16:01Z"
  }
}