CVE-2026-72020

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the ip vs conn new() function where ip vs conn objects allocated via kmem cache alloc() do not have their init seq and previous delta fields within the ip vs seq structures fully initialized. When connections are learned from a sync message that omits IPVS OPT SEQ DATA, the connection may be hashed with sequence flags set while containing stale slab data. Subsequently, when an IPVS application helper processes packets for such a connection, the vs fix seq() and vs fix ack seq() functions use these uninitialized values to rewrite TCP sequence numbers. This can allow a malformed sync message to cause forwarded packets to carry stale slab bytes in their TCP sequence and acknowledgment numbers, potentially corrupting the forwarded TCP flow.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.