Threats affecting pkg:cargo/github/Keats/jsonwebtoken

CVE-2026-25537 is a medium severity type confusion vulnerability in the Rust jsonwebtoken library versions prior to 10.3.0. The flaw arises from improper handling of standard JWT claims like 'nbf' or 'exp' when they are provided with incorrect JSON types, causing the library to treat malformed claims as absent. This leads to bypassing critical time-based validations such as 'Not Before' checks, potentially allowing attackers to circumvent authentication and authorization controls. The vulnerability does not require authentication or user interaction and can be exploited remotely. It has been patched in version 10.3.0. European organizations using affected versions of jsonwebtoken in their Rust applications, especially those relying on JWT for security, are at risk.