GHSA-jc85-fpwf-qm7x — expr-eval
Fix: silentmatt/expr-eval#288GHSA-jc85-fpwf-qm7x is a Code Injection vulnerability in expr-eval. 1 public exploit reference exists, so weaponization risk is real. A fix is available for expr-eval — see the affected versions and patch details below.
expr-eval does not restrict functions passed to the evaluate function
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-jc85-fpwf-qm7x.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
expr-evalnpmexpr-eval-forknpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | expr-eval | all versions | No fix |
| 📦npm | expr-eval-fork | all versions | 3.0.1npm install expr-eval-fork@3.0.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for expr-eval, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
No patched version of expr-eval has shipped for GHSA-jc85-fpwf-qm7x yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-jc85-fpwf-qm7x can be triaged on real exposure rather than presence alone.
Tailored to GHSA-jc85-fpwf-qm7x. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-jc85-fpwf-qm7x in your dependencies?
O3 Security finds GHSA-jc85-fpwf-qm7x across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.