CVE Catalog

CVE-2026-81829

MediumCVSS 5.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.58%

46th percentile - higher than 46% of all known CVEs

Summary

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.

Risk Assessment

An attacker can read non-public endpoints or internal data reachable on the same origin before JWT signature verification, potentially leading to information disclosure. The risk affects the confidentiality of internal data.

Recommendation

Update SmallRye JWT to a version containing the fix for AwsAlbKeyResolver. Verify the AWS_ALB key provider configuration and consider restricting access to internal endpoints.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS