A flaw was found in SmallRye JWT's AwsAlbKeyResolver, which is used by applications to verify JSON Web Tokens signed by AWS Application Load Balancers

Overview

A flaw was found in SmallRye JWT's AwsAlbKeyResolver, which is used by applications to verify JSON Web Tokens signed by AWS Application Load Balancers. When the AWS_ALB key provider is configured, the resolver constructs the key-fetch URL by directly concatenating the attacker-controlled kid header value from an inbound JWT without sanitizing path traversal characters or query-string separators. This allows an unauthenticated remote attacker to force the application server to issue GET requests to arbitrary paths on the same origin as the configured key endpoint. As a result, non-public endpoints or internal data reachable on that origin may be read by the attacker before JWT signature verification takes place.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · affected: Exploit Intelligence, Red Hat build of Apicurio Registry 3, Red Hat build of Quarkus, Red Hat JBoss Enterprise Application Platform 8, Red Hat JBoss Enterprise Application Platform Expansion Pack · no fix planned: Red Hat build of Apicurio Registry 3, Exploit Intelligence, Red Hat build of Quarkus, Red Hat JBoss Enterprise Application Platform 8, … · updated 2026-09-17 · vex