CVE-2026-52981
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk41th percentile — higher than 41% of all known CVEs
Summary
In the Linux kernel, the neigh_xmit function leaks an skb when called for an uninitialized neighbor table (e.g., NEIGH_ND_TABLE with IPv6 disabled). The function does not free the packet, and its return value is ignored by the caller (e.g., MPLS). The patch ensures neigh_xmit always takes ownership of the skb and frees or transmits it.
Risk Assessment
Memory leak can lead to system resource exhaustion and potential denial of service (DoS) if this code path is triggered repeatedly.
Recommendation
Apply the latest Linux kernel patch addressing CVE-2026-52981. Update your system to a kernel version containing this commit.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: neigh: let neigh_xmit take skb ownership neigh_xmit always releases the skb, except when no neighbour table is found. But even the first added user of neigh_xmit (mpls) relied on neigh_xmit to release the skb (or queue it for tx). sashiko reported: If neigh_xmit() is called with an uninitialized neighbor table (for example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT and bypasses its internal out_kfree_skb error path. Because the return value of neigh_xmit() is ignored here, does this leak the SKB? Assume full ownership and remove the last code path that doesn't xmit or free skb.