CVE-2026-43452 netfilter: x_tables: guard option walkers against 1-byte tail reads
A missing bounds check in Linux kernel netfilter option walkers allows out-of-bounds reads, potentially causing crashes or information leaks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43452?
CVE-2026-43452 is a high-severity memory corruption vulnerability in Linux kernel, published on 8 May 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: x_tables: guard option walkers against 1-byte tail reads
When the last byte of options is a non-single-byte option kind, walkers that advance with i += op[i + 1] ? : 1 can read op[i + 1] past the end of the option area.
Add an explicit i == optlen - 1 check before dereferencing op[i + 1] in xt_tcpudp and xt_dccp option walkers.
Weakness: CWE-125
Which versions are affected by CVE-2026-43452?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43452?
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-2026-43452 being exploited?
There is no known exploitation of CVE-2026-43452 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43452, DEBIAN-CVE-2026-43452, GHSA-3jfw-v6mf-ccwx, ROOT-OS-DEBIAN-11-CVE-2026-43452, ROOT-OS-UBUNTU-2204-CVE-2026-43452, ROOT-OS-UBUNTU-2404-CVE-2026-43452 and 1 more.