CVE-2026-80875 ipvs: use parsed transport offset in TCP state lookup
An attacker can cause memory corruption or denial of service in the Linux kernel IPVS module by sending crafted IPv6 packets with extension headers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80875?
CVE-2026-80875 is a memory corruption vulnerability in Linux, published on 4 Sep 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:
ipvs: use parsed transport offset in TCP state lookup
TCP state handling reparses the skb to find the TCP header. For IPv6 it uses sizeof(struct ipv6hdr), while the surrounding IPVS code already parsed the packet with ip_vs_fill_iph_skb() and has the real transport-header offset in iph.len.
This makes TCP state handling look at the wrong bytes when an IPv6 packet carries extension headers. Use the parsed transport offset passed down from ip_vs_set_state() when reading the TCP header.
For IPv4 and for IPv6 packets without extension headers, the passed offset matches the previous value.
Which versions are affected by CVE-2026-80875?
How do I fix CVE-2026-80875?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-80875 being exploited?
There is no known exploitation of CVE-2026-80875 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80875, DEBIAN-CVE-2026-80875, GHSA-x476-x69x-m4jr, UBUNTU-CVE-2026-80875.