orval: Improper Control of Generation of Code
CVE-2026-23947 is a critical-severity improper control of generation of code vulnerability in orval from Orval-labs, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected orval versions: >= 8.0.0-rc.0, < 8.0.2; < 7.19.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.84% chance of exploitation within 30 days, higher than 58% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of orval you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Orval-labs | orval | >= 8.0.0-rc.0, < 8.0.2; < 7.19.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Orval generates type-safe JS clients (TypeScript) from any valid OpenAPI v3 or Swagger v2 specification. Versions prior to 7.19.0 until 8.0.2 are vulnerable to arbitrary code execution in environments consuming generated clients. This issue is similar in nature to CVE-2026-22785, but affects a different code path in @orval/core that was not addressed by CVE-2026-22785's 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. Orval 7.19.0 and 8.0.2 contain a fix for the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/orval-labs/orval/releases/tag/v8.0.2Product, Release Notes
Other vulnerabilities in orval
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.1 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Improper Control of Generation of Code vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 9.9 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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