CVE-2026-28794 oRPC: Prototype Pollution in `@orpc/client` via `StandardRPCJsonSerializer` Deserialization
Remote attackers can exploit prototype pollution in the oRPC client deserializer to achieve code execution, bypass authentication, or cause denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-28794?
CVE-2026-28794 is a critical unsafe deserialization vulnerability in middleapi orpc, published on 6 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
oRPC is an tool that helps build APIs that are end-to-end type-safe and adhere to OpenAPI standards. Prior to version 1.13.6, a prototype pollution vulnerability exists in the RPC JSON deserializer of the @orpc/client package. The vulnerability allows unauthenticated, remote attackers to inject arbitrary properties into the global Object.prototype. Because this pollution persists for the lifetime of the Node.js process and affects all objects, it can lead to severe security breaches, including authentication bypass, denial of service, and potentially Remote Code Execution. This issue has been patched in version 1.13.6.
Weakness: CWE-1321
Which versions are affected by CVE-2026-28794?
2 open source packages ship an affected version, including @orpc/client. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@orpc/client npm | All versions | 1.13.6 |
@orpc/client npm | All versions | 1.13.6 |
Products include Orpc Orpc.
How do I fix CVE-2026-28794?
Upgrade @orpc/client to 1.13.6 or later.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-28794 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28794 exists.
Other vulnerabilities in middleapi orpc
Sources
Also known as GHSA-m272-9rp6-32mc.