Cisco Confirms Active Exploitation of Two Catalyst SD

CVE-2026-20079 is an authentication bypass (CWE-288) in the web interface of Cisco Secure Firewall Management Center (FMC) Software, caused by an improper system process created at boot time. An unauthenticated, remote attacker can exploit it by sending crafted HTTP requests to the FMC web interface, which allows the execution of script files and commands on the device. A successful exploit grants the attacker root access to the underlying operating system, giving full control of the management platform (CVSS 3.1: 10.0, network-exploitable, no privileges or user interaction required, scope changed). The flaw affects Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management deployments. Cisco has confirmed the vulnerability is being exploited in active attacks, it carries a 35.9% EPSS score (98th percentile), and CISA added it to the Known Exploited Vulnerabilities catalog on 2026-09-09.

Do: Upgrade FMC (and SCC Firewall Management tenants) to the fixed release specified in Cisco's advisory, prioritizing internet-exposed or externally reachable management interfaces; CISA KEV action applies to federal agencies under BOD 26-04. Until patching, restrict FMC web interface access to trusted management networks and VPNs and check devices for signs of exploitation such as unexpected script execution, unfamiliar processes, or root-level changes. Triage per CISA's Forensics Triage Requirements if compromise is suspected.

Cisco Catalyst SD-WAN Manager (the platform formerly known as vManage) contains an incorrect use of privileged APIs flaw (CWE-648) stemming from improper file handling on its API interface. An attacker exploits it by uploading a malicious file through the API interface onto the local file system of an affected system. A successful exploit allows the attacker to overwrite arbitrary files on the system and gain vmanage user privileges, which typically means administrative control of the SD-WAN management plane. Any organization running Catalyst SD-WAN Manager, whether on-premises appliances or virtual instances managing an SD-WAN overlay or instances hosted in Cisco's cloud, is potentially affected; CISA has not published affected version ranges or a CVSS score, and the flaw was disclosed alongside other Cisco product vulnerabilities. The vulnerability was added to CISA's Known Exploited Vulnerabilities catalog on 2026-04-20, indicating exploitation in the wild, EPSS estimates a 24.6% probability of exploitation within 30 days (98th percentile), no public proof-of-concept is known, and ransomware use is unknown.

Do: Follow CISA's Emergency Directive 26-03 and the Hunt & Hardening Guidance for Cisco SD-WAN Devices to identify exposed SD-WAN Manager instances and hunt for signs of exploitation, and prioritize applying the fixed releases cited in Cisco's advisory once version ranges are published. Until patched, restrict and monitor access to the SD-WAN Manager API interface; organizations using Cisco's cloud-hosted SD-WAN service should adhere to the applicable BOD 22-01 cloud guidance or discontinue use if mitigations are unavailable.

Cisco Catalyst SD-WAN Manager, the central management and monitoring platform for Cisco SD-WAN fabrics (formerly known as vManage), contains a sensitive-information-exposure flaw (CWE-200) that allows remote attackers to view sensitive information on affected systems. The available data does not specify the exact trigger path or authentication requirements, but the flaw is remotely exploitable by unauthorized actors. An attacker gains access to sensitive information held on the management platform, which aggregates inventory, configuration, and telemetry for an entire SD-WAN overlay, potentially aiding follow-on attacks. Any organization running an affected release of Cisco Catalyst SD-WAN Manager is in scope. CISA added the vulnerability to its Known Exploited Vulnerabilities catalog on 2026-04-20, confirming exploitation in the wild, and EPSS assigns a 31.4% probability of exploitation within 30 days (98th percentile), although CVSS scoring is pending and no public proof-of-concept is known.

Do: Inventory your environment for internet-exposed Catalyst SD-WAN Manager instances and review access logs for signs of unauthorized retrieval of sensitive information, since the flaw is listed as exploited in the wild. Apply the vendor fix referenced in Cisco's advisory for CVE-2026-20133 when available, and follow CISA's Emergency Directive 26-03 and the CISA 'Hunt & Hardening Guidance for Cisco SD-WAN Devices'; federal agencies must adhere to applicable BOD 22-01 mitigation timelines or discontinue use of the product if mitigations are unavailable.

A flaw in the peering authentication mechanism of Cisco Catalyst SD-WAN Controller (formerly vSmart), Manager (formerly vManage), and Validator (formerly vBond) allows an unauthenticated, remote attacker to bypass authentication by sending crafted requests to an affected system. A successful exploit grants the attacker access as an internal, high-privileged, non-root user on the SD-WAN Controller, from which they can reach NETCONF and manipulate the network configuration of the entire SD-WAN fabric. Any organization operating these Cisco SD-WAN control-plane components is affected, and the critical CVSS 10.0 score reflects full network scope with no privileges or user interaction required. The flaw is confirmed exploited in the wild: CISA added it to the KEV on 2026-02-25, Cisco has confirmed active exploitation (including a compromise of a communications service provider), and Five Eyes allies have issued an active-exploitation warning, with EPSS at 88.2% (100th percentile).

Do: Upgrade affected Catalyst SD-WAN Controller, Manager, and Validator components per Cisco's PSIRT advisory (fixed versions are not specified in this data), and prioritize patching given confirmed in-the-wild exploitation. Follow CISA Emergency Directive 26-03 and the CISA Hunt & Hardening Guidance for Cisco SD-WAN Devices: hunt for compromise indicators such as unexpected high-privileged non-root logins and unauthorized NETCONF configuration changes, and restrict internet exposure of SD-WAN management interfaces. Where mitigations are unavailable, adhere to applicable BOD 22-01 cloud guidance or discontinue use of the product.

CVE-2026-20131 is a deserialization of untrusted data flaw (CWE-502) in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management. An unauthenticated, remote attacker can trigger it by sending crafted serialized data to the exposed management interface. Successful exploitation allows the attacker to execute arbitrary Java code as root on the affected device, giving full control of the central platform that manages Cisco firewall policy. Any organization running FMC or managing firewalls through SCC is potentially affected; specific version ranges have not yet been published in the available data. The flaw was added to CISA KEV on 2026-03-19 with known ransomware use, and EPSS assigns a ~31% probability of exploitation within 30 days (98th percentile), though no public proof-of-concept is known.

Do: Check Cisco's advisory for fixed releases and upgrade all FMC and SCC-managed deployments as soon as patched versions are identified, since version ranges are not yet in this data; until patched, restrict the FMC/SCC web-based management interface to trusted management networks or VPN access. Given the CISA KEV listing (added 2026-03-19) with known ransomware use, treat this as a high-priority patch and confirm whether BOD 22-01 remediation deadlines apply to your organization.