CVE-2026-52981 neigh: let neigh_xmit take skb ownership
A memory leak in the Linux kernel's neigh_xmit function can lead to resource exhaustion and denial of service when IPv6 is disabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-52981?
CVE-2026-52981 is a high-severity denial of service vulnerability in Linux kernel, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-401
Which versions are affected by CVE-2026-52981?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-52981?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-52981 being exploited?
There is no known exploitation of CVE-2026-52981 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-52981, DEBIAN-CVE-2026-52981, GHSA-36qf-2q77-7jh9, ROOT-OS-DEBIAN-11-CVE-2026-52981, ROOT-OS-DEBIAN-12-CVE-2026-52981, ROOT-OS-UBUNTU-2204-CVE-2026-52981 and 2 more.