CVE-2026-97417 netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()
A kernel bug in netfilter TCP SACK handling causes unaligned memory access, potentially leading to system crashes or instability.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97417?
CVE-2026-97417 is a high-severity vulnerability in Linux, published on 24 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:
netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()
The timestamp-only fast path dereferences the option stream as *(__be32 *)ptr, which assumes 4-byte alignment that the TCP option stream does not guarantee. Use get_unaligned_be32() instead, which reads the value safely and already returns host byte order, so the htonl() on the comparison constant can be dropped.
This matches the existing get_unaligned_be32() use later in the same function.
Which versions are affected by CVE-2026-97417?
How do I fix CVE-2026-97417?
Apply the vendor's patch.
Is CVE-2026-97417 being exploited?
There is no known exploitation of CVE-2026-97417 in the wild and no public exploit code.
Sources
Also known as AZL-103628, BELL-CVE-2026-97417, DEBIAN-CVE-2026-97417, GHSA-86rv-j9hx-pv73, UBUNTU-CVE-2026-97417.