CVE-2026-23451: 
Linux Kernel vulnerability analysis and mitigation

CVE-2026-23451 is a Linux kernel vulnerability involving a potential infinite loop in the bond_header_parse() function within the bonding network driver. When a stack of two bonding devices is configured, skb->dev always points to the hierarchy top, causing the function to loop indefinitely. The vulnerability affects Linux kernel versions up to and including 6.18.19, 6.19.9, and 7.0-rc4, with fixes available in 6.18.20, 6.19.10, and 7.0-rc5. It was disclosed on April 3, 2026, and carries a CVSS v3.1 base score of 7.5 (High) (GitHub Advisory).

The root cause is classified as CWE-835 (Loop with Unreachable Exit Condition / Infinite Loop). In the Linux kernel's bonding subsystem, bond_header_parse() calls the (struct header_ops)->parse() method, which uses skb->dev to determine the network device. When two bonding devices are stacked, skb->dev consistently references the top of the device hierarchy rather than the leaf device, causing unbounded recursive calls. The fix introduces a new const struct net_device *dev parameter to the (struct header_ops)->parse() method, ensuring recursion is bounded and the correct leaf-level parse method is ultimately invoked (GitHub Advisory).

Successful triggering of this vulnerability results in a denial-of-service condition through resource exhaustion or system hang on affected Linux hosts. There is no confidentiality or integrity impact — only availability is affected. Systems utilizing multi-level bonded network interface configurations (e.g., bond-over-bond setups) are specifically at risk of service interruption, potentially impacting network-dependent workloads and high-availability infrastructure (GitHub Advisory).

Update the Linux kernel to a patched version: 6.18.20, 6.19.10, or 7.0-rc5 and later. Patches are available via the following stable kernel commits: 946bb6cacf0ccada7bc80f1cfa07c1ed79511c1c, 4172a7901cf43fe1cc63ef7a2ef33735ff7b7d13, 9b49c854f14f5e2d493e562a1e28d2e57fe37371, and b7405dcf7385445e10821777143f18c3ce20fa04. As a configuration-level workaround, administrators should audit and avoid stacked (bond-over-bond) bonding device configurations where possible until patching is complete. Monitor system logs and interface performance for signs of infinite loops or CPU exhaustion on bonded interfaces (GitHub Advisory).