A Linux kernel vulnerability in TCP networking could allow DoS > CVE-2019-11477 is considered an Important severity, whereas CVE-2019-11478 and CVE-2019-11479 are considered a Moderate severity. The first two are related to the Selective Acknowledgement (SACK) packets combined with Maximum Segment Size (MSS), the third solely with the Maximum Segment Size (MSS). Vulnerable code exists in https://github.com/torvalds/linux/blob/master/include/linux/skbuff.h This might stick around in various embedded hardware, which could be more disasterous if DoS'ed, but it's too early to tell.

Jonathan Looney discovered that the TCP retransmission queue implementation in tcp_fragment in the Linux kernel could be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commit f070ef2ac66716357066b683fb0baf55f8191a2e.