CVE-2025-13204 PUBLISHED

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.

• https://www.npmjs.com/package/expr-eval-fork
• https://github.com/silentmatt/expr-eval
• https://github.com/jorenbroekema/expr-eval
• https://www.huntr.dev/bounties/1-npm-expr-eval/
• https://github.com/SECCON/SECCON2022_final_CTF/blob/main/jeopardy/web/babybox/solver/solver.py
• https://github.com/silentmatt/expr-eval/pull/252/files
• https://github.com/vladko312/extras/blob/f549d505af300fd74a01b46fab2102990ff1c14d/expr-eval.py

• CWE-1321 Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')