Prototype pollution in expr-eval and expr-eval-fork - CVE-2025-13204
Published: January 7, 2026
Vulnerability identifier: #VU121009
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-13204
CWE-ID: CWE-1321
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
expr-eval
expr-eval-fork
Red Hat Enterprise Linux Server - AUS
IBM Business Automation Manager Open Editions
grafana-pcp (Red Hat package)
expr-eval-fork
Red Hat Enterprise Linux Server - AUS
IBM Business Automation Manager Open Editions
grafana-pcp (Red Hat package)
How to mitigate CVE-2025-13204
The vulnerability is resolved in expr-eval-fork library.
expr-eval-fork - update to 2.0.2
IBM Business Automation Manager Open Editions - update to 9.3.1
grafana-pcp (Red Hat package) - update to 1.0.5-5.el8_2
IBM Business Automation Manager Open Editions - update to 9.3.1
grafana-pcp (Red Hat package) - update to 1.0.5-5.el8_2
External 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