CVE-2026-98233 net/packet: clear RX owner on VNET header error
A remote attacker can cause a denial of service by sending malformed UDP GSO packets that leave a TPACKET_V2 ring slot permanently claimed, blocking subsequent valid packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98233?
CVE-2026-98233 is a denial of service vulnerability in Linux, published on 6 Oct 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:
net/packet: clear RX owner on VNET header error
Commit 61fad6816fc1 ("net/packet: tpacket_rcv: avoid a producer race condition") added rx_owner_map and made tpacket_rcv() claim a V1 or V2 ring slot before converting the virtio-net header. If the conversion fails, the drop path leaves the slot claimed.
With a one-frame TPACKET_V2 ring, an unsupported UDP GSO packet leaves the only slot unavailable, so the ring also drops the next valid packet.
Clear the ownership bit on this error path. TPACKET_V3 already clears its block state here.
Which versions are affected by CVE-2026-98233?
How do I fix CVE-2026-98233?
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-2026-98233 being exploited?
There is no known exploitation of CVE-2026-98233 in the wild and no public exploit code.
Sources
Also known as AZL-106224, BELL-CVE-2026-98233, DEBIAN-CVE-2026-98233, GHSA-6w2p-qxh2-6wc3, UBUNTU-CVE-2026-98233.