An integer underflow issue was found in the QEMU VNC server while processing ClientCutText messages in the extended format. A malicious client could use this flaw to make QEMU unresponsive by sending a specially crafted payload message, resulting in a denial of service.
An off-by-one read/write issue was found in the SDHCI device of QEMU. It occurs when reading/writing the Buffer Data Port Register in sdhci_read_dataport and sdhci_write_dataport, respectively, if data_count == block_size. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition.
Patch at above URL, doesn't seem to have made it into git yet.