A parsing vulnerability for the MessageSet type in the ProtocolBuffers versions prior to and including 3.16.1, 3.17.3, 3.18.2, 3.19.4, 3.20.1 and 3.21.5 for protobuf-cpp, and versions prior to and including 3.16.1, 3.17.3, 3.18.2, 3.19.4, 3.20.1 and 4.21.5 for protobuf-python can lead to out of memory failures. A specially crafted message with multiple key-value per elements creates parsing issues, and can lead to a Denial of Service against services receiving unsanitized input. We recommend upgrading to versions 3.18.3, 3.19.5, 3.20.2, 3.21.6 for protobuf-cpp and 3.18.3, 3.19.5, 3.20.2, 4.21.6 for protobuf-python. Versions for 3.16 and 3.17 are no longer updated. A parsing issue with binary data in protobuf-java core and lite versions prior to 3.21.7, 3.20.3, 3.19.6 and 3.16.3 can lead to a denial of service attack. Inputs containing multiple instances of non-repeated embedded messages with repeated or unknown fields causes objects to be converted back-n-forth between mutable and immutable forms, resulting in potentially long garbage collection pauses. We recommend updating to the versions mentioned above