CVE-2026-64515 wifi: mac80211: fix MLE defragmentation
A heap buffer overflow in the Linux kernel's Wi-Fi mac80211 module allows attackers to potentially execute code or cause a system crash via crafted multi-link elements.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64515?
CVE-2026-64515 is a high-severity memory corruption vulnerability in Linux, published on 25 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix MLE defragmentation
If either reconf or EPCS multi-link element (MLE) is contained in a non-transmitted profile, the defragmentation routine is called with a pointer to the defragmented copy, but the original elements.
This is incorrect for two reasons: - if the original defragmentation was needed, it will not find the correct data - if the original frame is at a higher address, the parsing will potentially overrun the heap data (though given the layout of the buffers, only into the new defragmentation buffer, and then it has to stop and fail once that's filled with copied data.
Fix it by tracking the container along with the pointer and in doing so also unify the two almost identical defragmentation routines.
Weakness: CWE-787
Which versions are affected by CVE-2026-64515?
How do I fix CVE-2026-64515?
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-2026-64515 being exploited?
There is no known exploitation of CVE-2026-64515 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-64515, DEBIAN-CVE-2026-64515, GHSA-x6wq-gx7f-g22h, ROOT-OS-UBUNTU-2204-CVE-2026-64515, UBUNTU-CVE-2026-64515.