CVE-2026-24112 identifies a buffer overflow vulnerability in the Tenda W20E router firmware version V4.0br_V15.11.0.6. The vulnerability occurs in the addWewifiWhiteUser function, which processes the 'userInfo' parameter using the C standard library function sscanf. The issue stems from the lack of size validation on the input passed to sscanf, allowing an attacker to supply a crafted 'userInfo' value that overflows the buffer allocated for this data. Buffer overflows can corrupt adjacent memory, potentially leading to arbitrary code execution, privilege escalation, or denial of service conditions on the affected device. Since the Tenda W20E is a consumer-grade wireless router, exploitation could allow attackers to compromise network traffic, intercept data, or disrupt network availability. The vulnerability does not require prior authentication, increasing its risk profile. No patches or firmware updates are currently linked, and no exploits have been reported in the wild, but the flaw is publicly disclosed and could be targeted by attackers. The lack of CVSS score necessitates a severity assessment based on technical impact and exploitability factors.

The buffer overflow vulnerability in Tenda W20E routers could have significant impacts on affected organizations and individuals. Exploitation may allow attackers to execute arbitrary code remotely, leading to full compromise of the router device. This can result in interception or manipulation of network traffic, exposure of sensitive data, and disruption of internet connectivity. For home users and small businesses relying on these routers, this could mean loss of confidentiality, integrity, and availability of their network communications. Additionally, compromised routers could be leveraged as entry points into larger corporate networks or used as part of botnets for broader attacks. The absence of authentication requirements and ease of exploitation increase the threat level. The impact extends to ISPs and service providers who distribute these devices, as widespread exploitation could degrade service quality and customer trust.

To mitigate CVE-2026-24112, affected users and organizations should prioritize the following actions: 1) Apply firmware updates from Tenda as soon as they become available that address this buffer overflow vulnerability. 2) Until patches are released, restrict access to the router’s management interfaces from untrusted networks, especially the internet, to reduce exposure. 3) Employ network segmentation to isolate vulnerable devices from critical systems. 4) Monitor network traffic for unusual activity that may indicate exploitation attempts. 5) If possible, disable or restrict the functionality related to the addWewifiWhiteUser feature or the processing of 'userInfo' parameters. 6) Encourage Tenda to implement secure coding practices, including input size validation and bounds checking for sscanf usage. 7) Consider replacing vulnerable devices with models that have a stronger security track record if timely patches are not forthcoming.