CVE-2026-107245: Buffer Overflow
Versa has confirmed a buffer overflow vulnerability in the IPsec implementation on VOS, aka Versa FlexVNF. Buffer Overflow Vulnerability Description When a maliciously crafted IKE Auth packet is sent to VOS, the vsmd process crashes, thereby resulting in a Denial of Service. An attacker can create a Denial-of-Service attack on the VOS appliances by crafting a malicious IKE Auth packet and sending it to the WAN interfaces on the VOS. During the IKE Authentication phase, if the IKE SA negotiation fails, and the size of the Remote ID is larger than the buffer size used to process the Remote ID, it will result in a crash of the vsmd process on the VOS appliance. What is impacted? VOS nodes configured with IPsec VPN profiles of type controller-staging-sdwan or remote-access-server using a WAN interface as the IPsec endpoint are vulnerable. (IPsec profiles configured with an overlay interface as the IPsec endpoint are not affected.) This configuration typically applies to all Controllers, Hub Controllers, and SSE Gateways. Additionally, site-to-site VPN profiles configured without a peer IP address, hostname, or FQDN are also vulnerable. What is not impacted? The VOS nodes listed above are not vulnerable if they are not accessible from the Internet.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Prevent Internet access to affected VOS nodes and their WAN interfaces; VOS nodes that are not accessible from the Internet are not vulnerable.
Event History
Frequently Asked Questions
Which VOS deployments are exposed to this denial-of-service condition?
Affected deployments include VOS nodes with controller-staging-sdwan or remote-access-server IPsec VPN profiles that use a WAN interface as the IPsec endpoint. This typically applies to Controllers, Hub Controllers, and SSE Gateways; site-to-site VPN profiles without a configured peer IP address, hostname, or FQDN are also vulnerable.
What does an attacker need to do to trigger the issue?
An attacker needs to send a maliciously crafted IKE Auth packet to a WAN interface on the VOS appliance. The crash occurs during IKE authentication when IKE SA negotiation fails and the Remote ID exceeds the buffer used to process it.
Are IPsec profiles using overlay interfaces affected?
No. IPsec profiles configured with an overlay interface as the IPsec endpoint are not affected.