CVE-2026-80847

A flaw was found in the Linux kernel's Transmission Control Protocol (TCP) implementation. The system incorrectly handles certain network route-derived advmss (advertised maximum segment size) values, which can become zero or too small. This can lead to a divide-by-zero error within the tcp_select_initial_window() function. An attacker could potentially exploit this to cause a Denial of Service (DoS) on the affected system.

This vulnerability is rated as Moderate severity because exploitation requires local privileges to manipulate routing metrics or establish network routes with specific maximum segment size values. A local attacker can trigger an unhandled arithmetic division error during TCP window calculations, causing a kernel panic and resulting in a denial of service. The flaw cannot be exploited remotely and does not lead to privilege escalation or unauthorized disclosure of data.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.