CVE-2026-20482 Overview
CVE-2026-20482 is a denial-of-service vulnerability in MediaTek WLAN Station (STA) firmware. Excessive logging behavior in the WLAN STA firmware can cause the affected system to become unresponsive. An attacker within wireless range of the target device can trigger the condition remotely across the adjacent network without authentication or user interaction. MediaTek addressed the flaw under Patch ID WCNCR00486814 and Issue ID MSV-6824. The weakness maps to [CWE-770] (Allocation of Resources Without Limits or Throttling).
Critical Impact
An unauthenticated attacker within wireless range can render affected devices unresponsive, disrupting wireless connectivity and dependent services.
Affected Products
- MediaTek chipsets implementing the vulnerable WLAN STA firmware (see MediaTek Security Bulletin August 2026 for the full product matrix)
- Devices integrating affected MediaTek WLAN firmware in station (client) mode
- Downstream OEM devices pending vendor firmware updates
Discovery Timeline
- 2026-08-03 - CVE-2026-20482 published to NVD
- 2026-08-03 - Last updated in NVD database
Technical Details for CVE-2026-20482
Vulnerability Analysis
The vulnerability resides in the WLAN STA firmware component that handles logging during wireless station operations. Unbounded or excessive logging consumes finite firmware resources. When triggered by adjacent network traffic, the logging path exhausts resources and the system stops responding. The flaw does not permit code execution or data disclosure. The impact is limited to availability, resulting in denial of service on the affected device.
Exploitation requires only wireless proximity to the target. The attacker does not need credentials, existing access, or user interaction on the victim device. Because the STA firmware processes incoming wireless frames before higher-layer authentication, the attack surface is exposed to any transmitter within radio range.
Root Cause
The root cause is [CWE-770], allocation of resources without limits or throttling. The WLAN STA firmware generates log entries in response to specific wireless events without applying rate limits or bounded buffers. Repeated triggering saturates logging resources and drives the firmware or host system into an unresponsive state.
Attack Vector
The attack vector is Adjacent Network. An attacker transmits crafted or repeated wireless frames that cause the STA firmware to invoke the vulnerable logging path. Sustained transmission keeps the device unresponsive for the duration of the attack. No authentication, privileges, or user interaction are required. Refer to the MediaTek Security Bulletin August 2026 for the technical description published by the vendor.
No verified proof-of-concept code is publicly available. The EPSS score at publication is 0.182%, reflecting a low estimated probability of near-term exploitation.
Detection Methods for CVE-2026-20482
Indicators of Compromise
- Sudden loss of wireless connectivity or WLAN interface hangs on devices using affected MediaTek chipsets
- Kernel or driver logs showing repeated WLAN STA firmware warnings preceding an unresponsive state
- Recurring device reboots or watchdog resets correlated with wireless activity from nearby transmitters
Detection Strategies
- Monitor host logs for high-frequency WLAN driver or firmware log entries that precede interface stalls
- Correlate wireless client disconnect storms with the presence of unknown transmitters in the vicinity
- Baseline normal WLAN firmware log volume and alert on sustained deviations
Monitoring Recommendations
- Collect kernel, dmesg, and vendor WLAN driver logs into a central log platform for retention and analysis
- Track device uptime and wireless interface reset counters as availability telemetry
- Include mobile and IoT endpoints running affected chipsets in wireless health monitoring dashboards
How to Mitigate CVE-2026-20482
Immediate Actions Required
- Inventory devices that ship with MediaTek WLAN chipsets and identify which are pending OEM firmware updates
- Apply the vendor firmware update referencing Patch ID WCNCR00486814 as soon as it is available from the device manufacturer
- Limit exposure of high-value devices to untrusted wireless environments until patches are deployed
Patch Information
MediaTek addressed the issue under Patch ID WCNCR00486814 (Issue ID MSV-6824). The fix is distributed through OEM firmware updates that integrate the corrected WLAN STA firmware. Consult the MediaTek Security Bulletin August 2026 and the specific device vendor for update availability and installation instructions.
Workarounds
- Disable the WLAN interface on affected devices when operating in untrusted radio environments
- Prefer wired connectivity for critical systems until firmware updates are applied
- Restrict physical proximity to sensitive devices where feasible, since exploitation requires adjacent-network access
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
