CVE-2026-53317 wifi: mt76: mt7921: Place upper limit on station AID
A missing upper limit on station AID in the mt7921 WiFi driver allows a remote attacker to crash the firmware via a modified hostapd, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53317?
CVE-2026-53317 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Jun 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: mt76: mt7921: Place upper limit on station AID
Any station configured with an AID over 20 causes a firmware crash. This situation occurred in our testing using an AP interface on 7922 hardware, with a modified hostapd, sourced from Mediatek's OpenWRT feeds.
In stock hostapd, station AIDs begin counting at 1, and this configuration is prevented with an upper limit on associated stations. However, the modified hostapd began allocation at 65, which caused the firmware to crash. This fix does not allow these AIDs to work, but will prevent the firmware crash.
This crash was only seen on IFTYPE_AP interfaces, and the fix does not appear to have an effect on IFTYPE_STATION behavior.
Which versions are affected by CVE-2026-53317?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53317?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-53317 being exploited?
There is no known exploitation of CVE-2026-53317 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-92034, BELL-CVE-2026-53317, DEBIAN-CVE-2026-53317, GHSA-86cw-5chj-gj42, ROOT-OS-DEBIAN-12-CVE-2026-53317, ROOT-OS-UBUNTU-2204-CVE-2026-53317 and 2 more.