Apache Mesos can be configured to require authentication to call the Executor HTTP API using JSON Web Token (JWT). In Apache Mesos versions pre-1.4.2, 1.5.0, 1.5.1, 1.6.0 the comparison of the generated HMAC value against the provided signature in the JWT implementation used is vulnerable to a timing attack because instead of a constant-time string comparison routine a standard `==` operator has been used. A malicious actor can therefore abuse the timing difference of when the JWT validation function returns to reveal the correct HMAC value.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.