CVE-2026-74669 ipvs: clear IPv4 options after rebasing tunnel ICMP errors
A stack out-of-bounds write in the Linux kernel IPVS module allows attackers to potentially execute code or cause a denial of service via crafted ICMP errors.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74669?
CVE-2026-74669 is a critical memory corruption vulnerability in Linux, published on 22 Aug 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: clear IPv4 options after rebasing tunnel ICMP errors
ip_vs_in_icmp() rebases an skb from the outer ICMP packet to the quoted original request before passing it to icmp_send(). However, IPCB(skb)->opt still describes the outer IPv4 header.
A timestamp option in the outer header can therefore leave an offset that points into the quoted transport header after the rebase. __ip_options_echo() treats a byte at that stale location as the option length and copies it into the fixed-size option storage on the __icmp_send() stack, causing a stack out-of-bounds write.
Clear the stale option metadata after resetting the network header. Keep the remaining control block fields, including the ingress interface used by the ICMP response path.
Which versions are affected by CVE-2026-74669?
How do I fix CVE-2026-74669?
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-2026-74669 being exploited?
There is no known exploitation of CVE-2026-74669 in the wild and no public exploit code.
Sources
Also known as AZL-97091, BELL-CVE-2026-74669, DEBIAN-CVE-2026-74669, GHSA-8jr6-vjx9-8g96, UBUNTU-CVE-2026-74669.