Cisco Talos Antivirus

CVE-2025-20333 is a buffer overflow (CWE-120) in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) software, caused by improper validation of user-supplied input in HTTP(S) requests. An attacker who already holds valid VPN user credentials can trigger it by sending crafted HTTP(S) requests to the device's VPN web interface; the flaw is remotely exploitable over the network with low attack complexity and no user interaction. A successful exploit allows arbitrary code execution as root, possibly resulting in complete compromise of the firewall or VPN gateway. Any organization running Cisco ASA or FTD software with the VPN web server enabled is affected. Exploitation is confirmed in the wild: the CVE was added to CISA's KEV on 2025-09-25, EPSS assigns a 70.7% probability of exploitation within 30 days (99th percentile), and Cisco and the UK NCSC have warned of real-world attacks (including RayInitiator and LINE VIPER malware deployment) that chain this flaw with at least one companion Cisco vulnerability.

Do: Inventory all ASA/FTD devices with the VPN web server reachable by users (especially internet-exposed ones) and upgrade to the fixed releases listed in the Cisco PSIRT advisory; where patching is delayed, apply Cisco's recommended mitigations and hunt for indicators of the reported attack chain (RayInitiator/LINE VIPER). Because exploitation requires valid VPN credentials, treat VPN user credentials on affected gateways as potentially compromised and force resets. US federal agencies must follow the mitigation steps in CISA Emergency Directive 25-03 and BOD 22-01 timelines for this KEV entry.

CVE-2026-20182 is a critical authentication flaw (CWE-287) in the control-connection peering authentication of Cisco Catalyst SD-WAN Controller (formerly vSmart), Manager (formerly vManage), and Validator (formerly vBond). Because the peering authentication mechanism does not work properly, an unauthenticated, remote attacker can send crafted requests during the control-connection handshake and log in to the controller as an internal, high-privileged, non-root user without valid credentials. With this access, the attacker can reach NETCONF and manipulate network configuration across the entire SD-WAN fabric. Any organization running these Catalyst SD-WAN control components is affected, and the flaw carries a CVSS 3.1 score of 10.0 and a 91.5% EPSS score. CISA added it to the Known Exploited Vulnerabilities catalog on 2026-05-14, confirming exploitation in the wild, amid a series of exploited Cisco SD-WAN zero-days including a compromise at a communications service provider.

Do: Upgrade affected Catalyst SD-WAN Controller, Manager, and Validator components to the fixed releases identified in Cisco's May 2026 advisory (version numbers are not provided in this data). Use the advisory's 'show control connections' guidance to inspect control-connection handshaking for anomalies and audit for unauthorized high-privileged non-root accounts and unexpected NETCONF sessions. Operators — especially federal agencies — should follow CISA Emergency Directive 26-03 and CISA's Hunt & Hardening Guidance for Cisco SD-WAN Devices, including restricting internet exposure of SD-WAN management interfaces until patched.