CVE-2026-2192 is a stack-based buffer overflow vulnerability identified in the Tenda AC9 router firmware version 15.03.06.42_multi. The vulnerability resides in the formGetRebootTimer function, which processes the sys.schedulereboot.start_time and sys.schedulereboot.end_time arguments. Improper handling of these parameters allows an attacker to overflow the stack buffer, potentially overwriting critical memory regions. This can lead to arbitrary code execution or cause the device to crash, resulting in denial of service. The vulnerability is remotely exploitable without requiring user interaction or prior authentication, making it particularly dangerous. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:H but likely a typo or means high privileges required), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). The exploit has been publicly disclosed, increasing the likelihood of exploitation attempts. No official patches or updates have been linked yet, so affected users must rely on mitigation strategies. The vulnerability affects a widely used consumer-grade router, which is often deployed in home and small office environments, increasing the potential attack surface. Given the critical nature of the flaw and the ease of remote exploitation, this vulnerability poses a significant risk to network security and device stability.

The impact of CVE-2026-2192 is substantial for organizations and individuals using the Tenda AC9 router. Successful exploitation can lead to full compromise of the router, allowing attackers to execute arbitrary code, potentially gaining control over the device. This can facilitate further attacks such as network eavesdropping, man-in-the-middle attacks, or pivoting to internal networks. Additionally, exploitation can cause denial of service by crashing the device, disrupting network connectivity. For enterprises relying on these routers for branch or remote office connectivity, this could result in operational downtime and data breaches. The vulnerability's remote exploitability without user interaction or authentication significantly increases the risk and potential attack surface. The public availability of the exploit code further elevates the threat, as less skilled attackers can leverage it. The confidentiality, integrity, and availability of network communications and connected devices are all at risk, potentially impacting sensitive data and business operations.

1. Immediately restrict remote access to the Tenda AC9 router management interface by disabling WAN-side management or limiting access to trusted IP addresses. 2. Implement network segmentation to isolate vulnerable devices from critical infrastructure and sensitive data. 3. Monitor network traffic for unusual requests targeting sys.schedulereboot.start_time and sys.schedulereboot.end_time parameters or other suspicious activity indicative of exploitation attempts. 4. Deploy intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics to detect exploitation attempts against this vulnerability. 5. Regularly check for firmware updates or security advisories from Tenda and apply patches as soon as they become available. 6. If patching is not immediately possible, consider replacing affected devices with more secure alternatives or using additional security controls such as VPNs to limit exposure. 7. Educate network administrators about this vulnerability and ensure secure configuration practices are followed to minimize attack vectors.