Vulnerability · Published Nov 14, 2025 · Assigned by certcc
CVE-2025-13204CVE-2025-13204
Critical 9.8
In plain English
A critical-severity prototype pollution in expr-eval from silentmatt. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 58% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.9%top 41.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | expr-eval | no fix listed | GHSA-8gw3-rxh4-v6jx |
| npm | expr-eval-fork | 2.0.2 | GHSA-8gw3-rxh4-v6jx |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| silentmatt | expr-eval | 0 – through 2.0.2 |
Weakness: CWE-1321 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- 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/ third-party-advisory
- https://github.com/SECCON/SECCON2022_final_CTF/blob/main/jeopardy/web/babybox/solver/solver.py
- https://github.com/silentmatt/expr-eval/pull/252/files patch
- https://github.com/vladko312/extras/blob/f549d505af300fd74a01b46fab2102990ff1c14d/expr-eval.py exploit