Critical rating for TCP flaw

The vulnerability resides in the kernel's TCP implementation, a core networking component present in virtually all Linux-based systems, from servers and cloud infrastructure to embedded and network equipment. Use-after-free bugs of this type typically arise when memory is deallocated while a pointer to it remains in use, potentially enabling arbitrary code execution or system crashes depending on the code path involved.

A CVSS score of 9.8 falls just below the maximum of 10.0, and indicates that a successful exploit could have severe consequences for confidentiality, integrity and availability, with low attack complexity and no user interaction or special privileges required, consistent with the scoring range.

Exposure across Linux deployments

Systems running affected versions of the kernel are exposed until a patched version is applied. Administrators of servers, cloud instances and network appliances are advised to check their kernel versions and apply vendor updates as they become available. Distributions typically ship corrected packages through their standard security update channels, and a restart is generally required for a patched kernel to take effect.

Because TCP is bound to network-facing services, systems with exposed network interfaces are the most relevant attack surface. Organizations operating internet-facing infrastructure are likely to prioritize patching given the critical rating attached to the flaw.

The assessment of the flaw drew on a review of 11 primary sources, including the vulnerability tracking record and related technical documentation. Details on specific exploitation activity or in-the-wild abuse were not established in the sources reviewed, and the practical exploitability of the bug in real-world configurations remains to be fully clarified.

The TCP use-after-free vulnerability CVE-2026-98432, with its CVSS 9.8 critical rating, is judged to be True.