CVE-2026-41690

18next-http-middleware is a middleware to be used with Node.js web frameworks like express or Fastify and also for Deno. Versions prior to 3.9.3 allow an unauthenticated HTTP client to pollute Object.prototype in the Node.js process hosting the middleware, via two unvalidated entry points that reach internal object-key writes: getResourcesHandler and missingKeyHandler. This can break authorisation checks (if (user.isAdmin) returning true for any user), cause type-confusion DoS, and depending on downstream code it can be chained into RCE.
Configurations

No configuration.

History

08 May 2026, 16:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-05-08 16:16

Updated : 2026-05-12 15:29


NVD link : CVE-2026-41690

Mitre link : CVE-2026-41690

CVE.ORG link : CVE-2026-41690


JSON object : View

Products Affected

No product.

CWE
CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')