SONICWALL has released a security bulletin detailing three critical vulnerabilities in its on‑premise Network Security Manager (NSM). The flaws, tracked as CVE-2026-78327, CVE-2026-78328 and CVE-2026-81939, carry a combined CVSSv3 high severity and affect NSM versions up to 4.3.0. The vulnerabilities enable bypassing authentication and arbitrary command execution, including an OS command injection on the NSM host and a Zip Slip path traversal. SonicWall notes that, at present, there are no public exploits observed in the wild, and cloud‑hosted NSM SaaS deployments are unaffected.
Improvements and mitigations have been released in NSM version 4.3.1-R4. The vendor confirms there are no temporary workarounds for vulnerable deployments, so applying the official update is advised. The affected on‑premises platforms include deployments on VMware, Hyper‑V, Azure and KVM hypervisors; however, cloud-based NSM SaaS instances are not impacted. The advisory SNWLID-2026-0015 provides deployment details and explicitly states there is no evidence these vulnerabilities are being exploited in the wild.
Organisations should prioritise upgrading to 4.3.1-R4 to remediate the three flaws and review any related security controls, logging, and access management to mitigate potential post‑update risks.