Security Resilience

CVE-2025-13204

Silentmatt Javascript Expression Evaluator

Public PoC
Published
14 November 2025
Modified
07 October 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0048 41th percentile
Risk Priority 56 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2025-13204 is a high-severity Prototype Pollution (CWE-1321) vulnerability in Silentmatt Javascript Expression Evaluator. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

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.

CWE(s)
CWE-1321

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1565 Data Manipulation Impact
Adversaries may insert, delete, or manipulate data in order to influence external outcomes or hide activity, thus threatening the integrity of the data.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-36573Shared CWE-1321
CVE-2024-22443Shared CWE-1321
CVE-2026-92779Shared CWE-1321
CVE-2025-58280Shared CWE-1321
CVE-2026-14893Shared CWE-1321
CVE-2026-25754Shared CWE-1321
CVE-2025-3193Shared CWE-1321
CVE-2024-21509Shared CWE-1321
CVE-2026-45302Shared CWE-1321
CVE-2026-48170Shared CWE-1321

Affected Assets

silentmatt
javascript expression evaluator
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V15.3.6

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
blocks

Secure SDLC practices directly require input validation and safe property assignment to prevent prototype pollution.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches prototype-pollution flaws before release.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prohibit unsafe prototype attribute assignment and require defensive checks.

A.8.32 Change management partial match
blocks

Change-management processes ensure security fixes for prototype-pollution issues are tracked and deployed.

References