CVE-2025-13204

HIGH

Silentmatt Javascript Expression Evaluator - Prototype Pollution

Title source: rule

Description

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.

References (7)

[Product] https://github.com/SECCON/SECCON2022_final_CTF/blob/main/jeopardy/web/babybox/solver/solver.py

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[Product] https://github.com/jorenbroekema/expr-eval

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[Product] https://github.com/silentmatt/expr-eval

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[Product] https://www.npmjs.com/package/expr-eval-fork

[Exploit, Third Party Advisory] https://www.huntr.dev/bounties/1-npm-expr-eval/

[Patch, Issue Tracking] https://github.com/silentmatt/expr-eval/pull/252/files

[Product] https://github.com/vladko312/extras/blob/f549d505af300fd74a01b46fab2102990ff1c14d/expr-eval.py

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Scores

CVSS v3 7.3

EPSS 0.0006

EPSS Percentile 17.3%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CISA SSVC

Vulnrichment

Exploitation poc

Automatable yes

Technical Impact partial

Details

CWE

CWE-1321

Status published

Products (3)

npm/expr-eval 0npm

npm/expr-eval-fork 0 - 2.0.2npm

silentmatt/javascript_expression_evaluator

Published Nov 14, 2025

Tracked Since Feb 18, 2026