Multiple vulnerabilities were discovered in PyJWT affecting various Ubuntu LTS releases and 26.10. These include improper handling of unknown key identifiers leading to potential denial of service via request amplification, improper handling of recursively nested JSON payloads causing application failure, malformed RSA key handling causing authentication failures or denial of service, and improper validation of OKP private key components allowing misuse of stolen tokens. Fixes are available in updated package versions for affected Ubuntu releases.