The verify function in Encryption/Symmetric.php in Malcolm Fell jwt before 1.0.3 does not use a timing-safe function for hash comparison, which allows attackers to spoof signatures via a timing attack.

JWT is a library to work with JSON Web Token and JSON Web Signature. Prior to versions 3.4.6, 4.0.4, and 4.1.5, users of HMAC-based algorithms (HS256, HS384, and HS512) combined with `Lcobucci\JWT\Signer\Key\LocalFileReference` as key are having their tokens issued/validated using the file path as hashing key - instead of the contents. The HMAC hashing functions take any string as input and, since users can issue and validate tokens, users are lead to believe that everything works properly. Versions 3.4.6, 4.0.4, and 4.1.5 have been patched to always load the file contents, deprecated the `Lcobucci\JWT\Signer\Key\LocalFileReference`, and suggest `Lcobucci\JWT\Signer\Key\InMemory` as the alternative. As a workaround, use `Lcobucci\JWT\Signer\Key\InMemory` instead of `Lcobucci\JWT\Signer\Key\LocalFileReference` to create the instances of one's keys.

jwt v5.4.3 was discovered to contain weak encryption. NOTE: this issue has been disputed on the basis that key lengths are expected to be set by an application, not by this library. This dispute is subject to review under CNA rules 4.1.4, 4.1.14, and other rules; the dispute tagging is not meant to recommend an outcome for this CVE Record.