SB2026010710 - Prototype pollution in expr-eval
Published: January 7, 2026
Security Bulletin ID
SB2026010710
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Prototype pollution (CVE-ID: CVE-2025-13204)
The vulnerability allows a remote attacker to execute arbitrary JavaScript code.
The vulnerability exists due to improper input validation. A remote attacker can pass specially crafted input to the application and perform prototype pollution, which can result in information disclosure or data manipulation.
Remediation
Install update from vendor's website.
References
- 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
- https://www.huntr.dev/bounties/1-npm-expr-eval/
- https://github.com/silentmatt/expr-eval/issues/266