CVE-2026-81829 — Smallrye-jwt: quarkus-smallrye-jwt: smallrye-jwt: unauthenticated same-origin ssrf via unsanitized jwt kid header in awsalbkeyresolver
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 prov…
Published: 2026-09-17 · CVSS: 5.3 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7