CVE-2026-53318

What it actually does

This is a Linux kernel denial-of-service flaw in the mt76 driver path for MediaTek MT7925 Wi-Fi hardware. The function mt7925_tx_check_aggr() dereferences the station pointer before confirming it is non-NULL, so a transmit aggregation code path that reaches this function without an associated station can trigger a kernel NULL pointer dereference. Depending on kernel configuration and runtime behavior, the result may be a kernel oops, system panic/reboot, Wi-Fi driver failure, or loss of wireless connectivity.

Why it matters to the business

Organizations with Linux systems using affected MediaTek MT7925 wireless adapters may experience unexpected endpoint crashes, reboots, or Wi-Fi outages. The current public risk signals are low—EPSS is low, there is no CISA KEV listing, no ransomware association, and no known mature public exploit—but the flaw still affects availability and should be remediated through normal kernel update processes, especially for laptops, kiosks, field systems, or other devices that rely on Wi-Fi for operations.

How an attack unfolds

An attacker first needs a target running a vulnerable Linux kernel with the mt76/mt7925 Wi-Fi driver loaded and the MT7925 wireless interface active. Exploitation consists of causing traffic or driver state that invokes the transmit aggregation check while the driver lacks a valid station object. Because the vulnerable code dereferences that station pointer before validating it, the kernel attempts to access a NULL address and generates an oops or panic. There is no indication from the provided data of code execution, privilege escalation, persistence, or confirmed exploitation in the wild; the practical impact is service disruption through a crash or wireless stack failure.

How to fix it

Update the Linux kernel to a version that includes the upstream mt76/mt7925 fix that moves the NULL check before dereferencing the station pointer in mt7925_tx_check_aggr(). Because no exact fixed package versions were provided, use the latest supported kernel from the relevant Linux distribution or vendor advisory and verify that it includes the CVE-2026-53318 fix. If immediate patching is not possible, reduce exposure by disabling the MT7925 Wi-Fi interface, using a wired connection or alternate wireless adapter, unloading the affected driver where operationally feasible, and limiting untrusted wireless environments until patched.

How to confirm the fix worked

Confirm exposure by checking whether systems use MediaTek MT7925 Wi-Fi hardware and load the mt76/mt7925 driver, then compare the installed kernel package against the distribution or vendor advisory for this issue. Validate remediation by confirming the updated kernel is installed and booted, the relevant mt76/mt7925 fix is included in the running kernel build, and normal Wi-Fi operation continues without kernel oops or call traces referencing mt7925_tx_check_aggr(). Useful checks include reviewing `uname -a`, installed kernel package metadata, `lspci` or `lsusb` hardware output, `lsmod` for mt7925/mt76 modules, and kernel logs after Wi-Fi stress or connectivity testing.

Typical attack path

1. Identify a Linux system using MediaTek MT7925 Wi-Fi hardware and a vulnerable kernel/mt76 driver version.
2. Ensure or wait until the wireless interface is active and handling transmit traffic.
3. Trigger traffic or connection state that reaches the mt7925_tx_check_aggr() transmit aggregation path without a valid station object.
4. Cause the driver to dereference the NULL station pointer.
5. Observe denial of service such as kernel oops, panic, reboot, driver reset, or loss of Wi-Fi connectivity.

How to detect it

This flaw is a denial-of-service condition and does not inherently create files, accounts, network beacons, or persistence artifacts. To determine whether it may have already been triggered, review kernel and system logs for NULL pointer dereference events, kernel oops or panic records, and call traces involving mt7925_tx_check_aggr(), mt7925, or mt76. Relevant log sources include `journalctl -k`, `/var/log/kern.log`, `/var/log/messages`, `/var/log/syslog`, crash dump directories, kdump/vmcore records, systemd journal entries, NetworkManager logs, and endpoint telemetry that records kernel panics or unexpected reboots. Correlate suspected crashes with Wi-Fi activity, association/disassociation events, driver resets, or sudden loss of wireless connectivity. Because there is no known mature exploit or KEV listing in the provided data, detection should focus on crash forensics and repeated availability events rather than looking for post-compromise behavior.

• mt7925_tx_check_aggr
• BUG: kernel NULL pointer dereference
• Oops: 0000
• Call Trace:
• RIP: mt7925_tx_check_aggr
• mt7925
• mt76
• mt7925e
• kernel panic
• panic_on_oops
• /var/log/kern.log
• /var/log/messages
• /var/log/syslog
• journalctl -k

What your security team should do

• Inventory Linux endpoints that use MediaTek MT7925 Wi-Fi adapters or load mt7925/mt76 wireless modules.
• Prioritize kernel updates for mobile endpoints, operational systems, kiosks, and devices that depend on Wi-Fi availability.
• Track the relevant Linux distribution/vendor advisory because exact fixed package versions vary by distribution and were not provided in the input.
• If patching is delayed, consider temporary mitigations such as disabling the affected Wi-Fi adapter, using wired networking, or avoiding untrusted wireless environments.
• Add monitoring for kernel oops/panic events and call traces mentioning mt7925_tx_check_aggr, mt7925, or mt76.
• Treat repeated crashes around Wi-Fi activity as potential exploitation or reliability-impacting abuse, even though current public exploit maturity is listed as none.