In FreeBSD 12.0-STABLE before r351264, 12.0-RELEASE before 12.0-RELEASE-p10, 11.3-STABLE before r351265, 11.3-RELEASE before 11.3-RELEASE-p3, and 11.2-RELEASE before 11.2-RELEASE-p14, the kernel driver for /dev/midistat implements a read handler that is not thread-safe. A multi-threaded program can exploit races in the handler to copy out kernel memory outside the boundaries of midistat's data buffer.

In FreeBSD 12.0-STABLE before r350828, 12.0-RELEASE before 12.0-RELEASE-p10, 11.3-STABLE before r350829, 11.3-RELEASE before 11.3-RELEASE-p3, and 11.2-RELEASE before 11.2-RELEASE-p14, a missing check in the function to arrange data in a chain of mbufs could cause data returned not to be contiguous. Extra checks in the IPv6 stack could catch the error condition and trigger a kernel panic, leading to a remote denial of service.

In FreeBSD 12.0-STABLE before r350637, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350638, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the bsnmp library is not properly validating the submitted length from a type-length-value encoding. A remote user could cause an out-of-bounds read or trigger a crash of the software such as bsnmpd resulting in a denial of service.

In FreeBSD 12.0-STABLE before r350619, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350619, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the bhyve e1000 device emulation used a guest-provided value to determine the size of the on-stack buffer without validation when TCP segmentation offload is requested for a transmitted packet. A misbehaving bhyve guest could overwrite memory in the bhyve process on the host.

In FreeBSD 12.0-STABLE before r350648, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350650, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the ICMPv6 input path incorrectly handles cases where an MLDv2 listener query packet is internally fragmented across multiple mbufs. A remote attacker may be able to cause an out-of-bounds read or write that may cause the kernel to attempt to access an unmapped page and subsequently panic.

BZ2_decompress in decompress.c in bzip2 through 1.0.6 has an out-of-bounds write when there are many selectors.