CVE-2026-43406 libceph: prevent potential out-of-bounds reads in process_message_header()
A maliciously corrupted message frame can cause out-of-bounds reads in the Linux kernel's Ceph client, potentially leading to crashes or data exposure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43406?
CVE-2026-43406 is a critical 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:
libceph: prevent potential out-of-bounds reads in process_message_header()
If the message frame is (maliciously) corrupted in a way that the length of the control segment ends up being less than the size of the message header or a different frame is made to look like a message frame, out-of-bounds reads may ensue in process_message_header().
Perform an explicit bounds check before decoding the message header.
Weakness: CWE-125
Which versions are affected by CVE-2026-43406?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43406?
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-2026-43406 being exploited?
There is no known exploitation of CVE-2026-43406 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43406, DEBIAN-CVE-2026-43406, GHSA-pfqf-x57j-qhgm, ROOT-OS-DEBIAN-11-CVE-2026-43406, ROOT-OS-UBUNTU-2204-CVE-2026-43406, ROOT-OS-UBUNTU-2404-CVE-2026-43406 and 1 more.