CVE-2026-22080 is a vulnerability categorized under CWE-319, which pertains to the cleartext transmission of sensitive information. Specifically, in Tenda's 300Mbps Wireless Router F3 and N300 Easy Setup Router models, certain firmware versions transmit administrative credentials encoded only with Base64 encoding over the network via the web-based management interface. Base64 encoding is not encryption but a reversible encoding scheme, meaning an attacker with network access can easily decode the credentials. This vulnerability arises because the routers do not properly secure the transmission channel or encrypt sensitive data, allowing an attacker on the same local area network (LAN) to perform a man-in-the-middle (MITM) attack or passive traffic capture to intercept these credentials. Once obtained, the attacker can gain unauthorized administrative access to the router, potentially altering configurations, intercepting or redirecting traffic, or launching further attacks within the network. The vulnerability affects multiple firmware versions of the F3 v3.0 and v4.0 models, indicating a persistent issue across releases. The CVSS 4.0 score of 8.7 reflects high severity, with an attack vector limited to adjacent network (AV:A), low attack complexity (AC:L), no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. No known exploits have been reported in the wild yet, but the vulnerability's nature makes it a prime candidate for exploitation in environments where these routers are deployed without additional network protections.

For European organizations, this vulnerability poses a significant risk to network security and operational integrity. Many small and medium enterprises (SMEs), as well as home offices, may use Tenda routers due to their affordability and ease of setup. An attacker gaining administrative access to these routers can manipulate network traffic, intercept sensitive communications, deploy malware, or create persistent backdoors. This can lead to data breaches, loss of confidentiality, disruption of business operations, and potential lateral movement within corporate networks. The impact is particularly critical for organizations handling sensitive personal data under GDPR, as unauthorized access could lead to regulatory penalties and reputational damage. Additionally, compromised routers can be leveraged as entry points for broader cyber espionage or ransomware campaigns targeting European infrastructure. The threat is amplified in environments where network segmentation is weak and monitoring is insufficient, allowing attackers to remain undetected after exploitation.

1. Immediate firmware updates: Organizations should monitor Tenda's official channels for patches addressing this vulnerability and apply them promptly to affected devices. 2. Network segmentation: Isolate router management interfaces on separate VLANs or subnets accessible only to trusted administrators to reduce exposure to local attackers. 3. Use of secure management protocols: Where possible, disable web-based management or restrict it to HTTPS with strong encryption and authentication mechanisms. 4. Implement network monitoring: Deploy intrusion detection/prevention systems (IDS/IPS) to detect unusual traffic patterns or unauthorized access attempts targeting router management interfaces. 5. Replace vulnerable hardware: For critical environments, consider replacing affected Tenda models with routers from vendors with stronger security track records and timely patch management. 6. Educate users and administrators: Raise awareness about the risks of using default or weak router configurations and the importance of securing network devices. 7. Employ VPNs or encrypted tunnels for remote management to prevent credential interception over local networks. 8. Regularly audit network devices and configurations to identify and remediate insecure setups.