CVE-2026-23947 — @orval/core
Fix: orval-labs/orval@9e5d935CVE-2026-23947 is a CWE-77 vulnerability in @orval/core. A fix is available for @orval/core — see the affected versions and patch details below.
Orval MCP client is vulnerable to code injection via unsanitized x-enum-descriptions in enum generation
Exploitation Status
No confirmed exploitation observed yet
- 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.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-23947.
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.
@orval/corenpmDescription
Impact
Arbitrary code execution in environments consuming generated clients
This issue is similar in nature to the recently-patched MCP vulnerability (CVE-2026-22785), but affects a different code path in @orval/core that was not addressed by that fix.
The vulnerability allows untrusted OpenAPI specifications to inject arbitrary TypeScript/JavaScript code into generated clients via the x-enumDescriptions field, which is embedded without proper escaping in getEnumImplementation(). I have confirmed that the injection occurs during const enum generation and results in executable code within the generated schema files.
Patches
Upgrade to Orval 8.0.2
References
An example OpenAPI showing the issue:
openapi: 3.0.4
info:
title: Enum PoC
version: "1.0.0"
paths:
/ping:
get:
operationId: ping
responses:
"200":
description: ok
content:
application/json:
schema:
$ref: "#/components/schemas/EvilEnum"
components:
schemas:
EvilEnum:
type: string
enum:
- PWNED
x-enumDescriptions:
- "pwned */ require('child_process').execSync('id'); /*"
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @orval/core | ≥ 8.0.0-rc.0&&< 8.0.2 | 8.0.2npm install @orval/core@8.0.2 |
| 📦npm | @orval/core | all versions | 7.19.0npm install @orval/core@7.19.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @orval/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @orval/core to 8.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23947 is resolved across your whole dependency graph.
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 CVE-2026-23947 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-23947. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-23947 in your dependencies?
O3 Security finds CVE-2026-23947 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.