CVE-2026-23098: 
Linux Kernel vulnerability analysis and mitigation

CVE-2026-23098 is a double-free vulnerability (CWE-415) in the Linux kernel's netrom module, specifically within the nr_route_frame() function. The flaw was published on February 4, 2026, and affects the Linux kernel from version 2.6.12 through multiple stable branches, with fixed versions including 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, and 6.18.8. It carries a CVSS v3.1 base score of 7.8 (High) with a local attack vector (Feedly, EUVD).

The root cause is improper memory management (CWE-415: Double Free) in the nr_route_frame() function of the Linux kernel's NET/ROM amateur radio networking module. When processing a routing frame, old_skb (a socket buffer) is freed immediately without first checking whether the nr_neigh->ax25 pointer is NULL. If nr_neigh->ax25 is NULL, the caller function subsequently attempts to free old_skb a second time, triggering a double-free condition. The fix requires adding a NULL check on nr_neigh->ax25 before freeing old_skb to prevent the second deallocation (Feedly, Kernel Patch). Exploitation requires local access with low privileges and no user interaction.

Successful exploitation of this vulnerability can result in kernel memory corruption, denial of service (system crash/kernel panic), or potential privilege escalation on affected Linux systems. The CVSS v3.1 scoring reflects high impacts to confidentiality, integrity, and availability. Because the vulnerability resides in a kernel networking module, exploitation could affect the stability of the entire system and potentially allow a local attacker to escalate privileges to root (Feedly).

Apply the official Linux kernel patches addressing this vulnerability. Fixed versions include: 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8, and 6.19-rc7 (Feedly, EUVD). Ubuntu has issued multiple security notices (USN-8162-1, USN-8180-1 through USN-8180-6, USN-8186-1, USN-8188-1, USN-8275-1, USN-8297-1) addressing this flaw (Ubuntu USN-8180-1). As a workaround for systems that cannot be immediately patched, consider disabling the NET/ROM (netrom) kernel module if it is not required (modprobe -r netrom), and restrict local user access to minimize exposure.

The vulnerability received standard coverage from Linux security tracking outlets including linuxsecurity.com and pro-linux.de, primarily in the context of Ubuntu kernel security advisories. No notable independent researcher commentary or significant social media discussion has been identified beyond routine vulnerability tracking (linuxsecurity.com).