CVE-2026-74340 wifi: wcn36xx: fix OOB read from firmware count in PRINT_REG_INFO indication
A malicious firmware response can trigger an out-of-bounds read in the wcn36xx Wi-Fi driver, potentially leaking kernel memory or causing a crash.
- 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-2026-74340?
CVE-2026-74340 is a high-severity memory corruption vulnerability in Linux, published on 15 Aug 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: wcn36xx: fix OOB read from firmware count in PRINT_REG_INFO indication
The firmware-controlled rsp->count field is used as the loop bound for indexing into the flexible rsp->regs[] array without validation against the message length. A count exceeding the actual data causes out-of- bounds reads from the heap-allocated message buffer.
Add a check that count fits within the received message.
Which versions are affected by CVE-2026-74340?
How do I fix CVE-2026-74340?
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-2026-74340 being exploited?
There is no known exploitation of CVE-2026-74340 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74340, DEBIAN-CVE-2026-74340, GHSA-9fwg-3fvg-fm8h, UBUNTU-CVE-2026-74340.