Fast DDS is a C++ implementation of the DDS (Data Distribution Service) standard of the OMG (Object Management Group ). Prior to versions 3.4.1, 3.3.1, and 2.6.11, when the security mode is enabled, modifying the DATA Submessage within an SPDP packet sent by a publisher causes an Out-Of-Memory (OOM) condition, resulting in remote termination of Fast-DDS. If t he fields of `PID_IDENTITY_TOKEN` or `PID_PERMISSIONS_TOKEN` in the DATA Submessage are tampered with — specifically by ta mpering with the the `vecsize` value read by `readOctetVector` — a 32-bit integer overflow can occur, causing `std::vector ::resize` to request an attacker-controlled size and quickly trigger OOM and remote process termination. Versions 3.4.1, 3 .3.1, and 2.6.11 patch the issue.