CVE-2026-90237

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

Description An issue exists in the netfilter nft ct module where early insertion of expectations into the expectations list for unconfirmed conntracks leads to stale entries. This occurs because conntrack extension reallocation causes the .pprev pointer to point to an incorrect hlist head. To resolve this, an internal connection tracking (ct) helper is introduced and attached to the conntrack entry to align custom expectation support with existing ct helpers. Additionally, a new function nf conntrack helper release() is exposed to properly release the allocated internal helper. The fix also ensures that expectation creation is restricted to this custom helper and modifies nf ct expect related() to prevent packet drops if expectation creation fails, making the process best-effort.

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