Threat actor leveraged Cisco SD-WAN zero-day since 2023 (CVE-2026-20127)
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2022-20775 | Path Traversal Privilege Escalation in Cisco SD-WAN Software CLI CVE-2022-20775 is a path traversal and improper access control flaw (CWE-22/CWE-25) in the CLI of Cisco SD-WAN Software that allows an authenticated, local attacker to gain elevated privileges. An attacker triggers it by running a maliciously crafted command in the application CLI, abusing weak access controls on CLI commands. A successful exploit yields arbitrary command execution as the root user, giving full control of the affected SD-WAN component. Organizations running Cisco SD-WAN / Catalyst SD-WAN components — SD-WAN Manager, vBond Orchestrator, vSmart Controller, and vEdge Cloud routers — are affected. The flaw is now being actively exploited: it was added to the CISA KEV catalog on 2026-02-25, prompting CISA Emergency Directive 26-03 and joint Five Eyes 'Hunt & Hardening' guidance, a public proof-of-concept exists, and EPSS estimates a 12.5% chance of exploitation within 30 days (96th percentile). Do: Upgrade affected SD-WAN components — Catalyst SD-WAN Manager, vBond Orchestrator, vSmart Controller, and vEdge Cloud — to the fixed releases listed in Cisco advisory cisco-sa-sd-wan-priv-E6e8tEdF, as there are no workarounds. Restrict CLI access to trusted administrators, review local accounts for unexpected additions or changes, and hunt for signs of compromise per CISA Emergency Directive 26-03 and CISA's Hunt & Hardening Guidance for Cisco SD-WAN Devices. If patched software or cloud-service mitigations are unavailable, follow BOD 22-01 guidance and consider discontinuing use of the affected components. | 7.8 | 12% | KEV PoC |
| largeon the order of tens of thousands of SD-WAN controller and edge deployments (10k–100k systems) | |
| CVE-2026-20127 | Authentication Bypass in Cisco Catalyst SD-WAN Controller, Manager, Validator 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. | 10.0 | 88% | KEV |
| large≈10,000–100,000 controller/manager/validator deployments across enterprise and service-provider SD-WAN fabrics (Cisco SD-WAN is a market-leading enterprise… |
Full article419 words · extracted from helpnetsecurity.com · click to collapse
A “highly sophisticated” cyber threat actor has been exploiting a zero-day authentication bypass vulnerability (CVE-2026-20127) in Cisco Catalyst SD-WAN Controller (formerly vSmart) and Cisco Catalyst SD-WAN Manager (formerly SD-WAN vManage), Cisco has announced today.
The vulnerability was reported by Australian Signals Directorate’s Australian Cyber Security Centre, who said that once the vulnerability was exploited, “the malicious actors add[ed] a rogue peer, and eventually gain[ed] root access to establish long-term persistence in SD-WANs.”
“This vulnerability exists because the peering authentication mechanism in an affected system is not working properly,” Cisco explained in the accompanying security advisory.
“An attacker could exploit this vulnerability by sending crafted requests to an affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric.”
In a separate blog post, Cisco’s Talos threat intelligence team tied this exploitation and post-compromise activity to a group they named “UAT-8616”.
“After the discovery of active exploitation of the 0-day in the wild, we were able to find evidence that the malicious activity went back at least three years (2023). Investigation conducted by intelligence partners identified that the actor likely escalated to root user via a software version downgrade. The actor then reportedly exploited CVE-2022-20775 before restoring back to the original software version, effectively allowing them to gain root access,” the team said.
“UAT-8616’s attempted exploitation indicates a continuing trend of the targeting of network edge devices by cyber threat actors looking to establish persistent footholds into high value organizations including Critical Infrastructure (CI) sectors.”
Investigation and remediation advice
The team has advised customers to check for indicators of CVE-2026-20127 exploitation and for unauthorized peer connections, and they have shared investigative guidance.
Simultaneously, the Australian Cyber Security Centre published mitigation advice and a threat hunt guide.
The US Cybersecurity and Infrastructure Security Agency has also issued an emergency directive “in response to a significant cyber threat targeting federal networks utilizing certain Cisco systems and software.”
The directive orders US federal civilian agencies to, “without delay”:
- Inventory all Cisco SD-WAN systems in use
- Collect virtual snapshots and logs of those systems, and patch them
- Hunt for evidence of compromise
- Implement measures outlined in Cisco’s Catalyst SD-WAN Hardening Guide.
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Text extracted automatically; images, tables and formatting may be missing. Original: https://www.helpnetsecurity.com/2026/02/25/cisco-sd-wan-zero-day-cve-2026-20127/