CVE-2025-26781 is a vulnerability identified in the Layer 2 (L2) protocol handling within various Samsung Exynos processors, including mobile, wearable, and modem variants such as the Exynos 9820, 9825, 980, 990, 850, 1080, 2100, 1280, 2200, 1330, 1380, 1480, 9110, W920, W930, and modem models 5123 and 5300. The issue stems from improper processing of Radio Link Control (RLC) Acknowledged Mode (AM) Protocol Data Units (PDUs). RLC AM is responsible for reliable data transfer over the air interface in cellular networks. Incorrect handling of these PDUs can cause the affected device to enter a Denial of Service (DoS) state, potentially disrupting network connectivity or causing system instability. The vulnerability affects the baseband processing components embedded in these chipsets, which are critical for cellular communication. No CVSS score has been assigned yet, and no patches or known exploits are currently reported. The vulnerability was reserved in February 2025 and published in October 2025, indicating recent discovery. Exploitation likely requires network-level access to the cellular interface but does not require user interaction, making it a significant risk for devices exposed to untrusted or hostile network environments. The broad range of affected chipsets suggests a wide impact across many Samsung devices, including smartphones and wearables that utilize these processors. The vulnerability could be leveraged by attackers to disrupt mobile communications, impacting both consumer and enterprise users.

For European organizations, the impact of CVE-2025-26781 could be substantial, especially for those heavily reliant on Samsung mobile and wearable devices for communication and operational continuity. A successful Denial of Service attack could interrupt cellular connectivity, leading to loss of voice, data services, and potentially critical communications. This disruption could affect sectors such as finance, healthcare, government, and logistics, where mobile connectivity is essential. Enterprises using Samsung devices for remote work or IoT deployments may experience operational downtime or degraded service quality. The inability to communicate securely or reliably could also increase the risk of secondary attacks or data loss. Additionally, mobile network operators and service providers in Europe could face increased support burdens and reputational damage if large numbers of devices are affected. The lack of current patches means organizations must rely on interim mitigations, increasing exposure window. The widespread use of Samsung devices in Europe, combined with advanced mobile infrastructure, amplifies the potential impact.

1. Monitor network traffic for unusual patterns or repeated RLC AM PDU anomalies that could indicate exploitation attempts. 2. Limit exposure of vulnerable devices to untrusted or public cellular networks where possible, using VPNs or private APNs to isolate critical devices. 3. Implement network-level filtering or anomaly detection at the mobile network operator level to detect and block malformed RLC PDUs. 4. Maintain an inventory of Samsung devices using affected Exynos chipsets to prioritize risk assessment and response. 5. Engage with Samsung and mobile network providers to obtain and deploy firmware or software updates as soon as patches become available. 6. Educate users and IT staff about the potential for service disruptions and establish incident response plans for mobile connectivity outages. 7. Consider deploying multi-SIM or multi-device redundancy for critical communications to mitigate single points of failure. 8. Collaborate with mobile network operators to understand network-level mitigations and threat intelligence related to this vulnerability.