CVE-2026-1157 is a buffer overflow vulnerability identified in the Totolink LR350 router firmware version 9.3.5u.6369_B20220309. The vulnerability resides in the setWiFiEasyCfg function of the /cgi-bin/cstecgi.cgi endpoint, specifically in the handling of the ssid parameter. An attacker can remotely send a specially crafted request manipulating the ssid argument to overflow the buffer, potentially overwriting memory and enabling arbitrary code execution or denial of service. The attack vector requires no user interaction and no prior authentication, making it remotely exploitable over the network. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required. Although no confirmed exploits in the wild have been reported, a public exploit is available, increasing the likelihood of exploitation attempts. The vulnerability affects a specific firmware version, emphasizing the need for timely patching or mitigation. The lack of official patch links suggests that vendors may still be working on a fix or that users must upgrade to a newer firmware version once released. This vulnerability poses a significant risk to networks relying on Totolink LR350 routers, especially in environments where these devices are exposed to untrusted networks or the internet.

For European organizations, exploitation of CVE-2026-1157 could lead to unauthorized remote code execution, allowing attackers to gain control over affected routers. This can compromise network confidentiality by intercepting or redirecting traffic, integrity by injecting malicious data, and availability by causing device crashes or network outages. Critical sectors such as government, healthcare, finance, and telecommunications could face severe disruptions if their network perimeter devices are compromised. The vulnerability's remote and unauthenticated nature increases the attack surface, especially for organizations with exposed management interfaces or insufficient network segmentation. Additionally, the availability of a public exploit raises the risk of automated scanning and exploitation campaigns targeting vulnerable devices across Europe. The impact extends beyond individual organizations, potentially affecting supply chains and critical infrastructure reliant on secure and stable network connectivity.

Organizations should immediately inventory their network devices to identify any Totolink LR350 routers running the vulnerable firmware version 9.3.5u.6369_B20220309. Until an official patch is released, network administrators should restrict access to the /cgi-bin/cstecgi.cgi endpoint by implementing firewall rules or access control lists limiting management interface exposure to trusted internal networks only. Disabling remote management features or changing default credentials can reduce exposure. Network segmentation should be enforced to isolate vulnerable devices from critical systems. Monitoring network traffic for unusual requests targeting the ssid parameter or the cgi-bin endpoint can help detect exploitation attempts. Organizations should subscribe to vendor advisories and CVE databases to apply firmware updates promptly once available. Where possible, replacing vulnerable devices with models from vendors with stronger security track records may be considered for long-term risk reduction.