CVE-2025-26399 SolarWinds Web Help Desk Overview and Takeaways
A critical vulnerability (CVE-2025-26399) has been identified in SolarWinds Web Help Desk, which allows unauthenticated remote attackers to execute arbitrary code on affected systems. Although CVE-2025-26399 was originally disclosed in 2025, recent reports confirm this vulnerability is now being actively exploited in the wild. This development significantly elevates the risk to impacted environments. Immediate remediation is required to prevent compromise.
What do I need to know?
- CVE ID: CVE-2025-26399
- Severity: Critical (CVSS 3.1 Score: 9.8)
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Impact: Full compromise of confidentiality, integrity, and availability
- Root Cause: Insecure deserialization of Untrusted Data (CWE-502) in the AjaxProxy component
Products & Systems Affected
- Earliest Patched Version:
12.8.7 Hotfix 1
- Exploit Status:
Actively exploited; listed in CISA’s Known Exploited Vulnerabilities Catalog
- Related CVEs:
CVE-2025-26399 is a bypass of patches for CVE-2024-28988 and CVE-2024-28986
What do I need to do?
We recommend the following steps to identify and remediate this vulnerability:
- Apply the vendor patch:
- Upgrade to SolarWinds Web Help Desk 12.8.7 Hotfix 1, or newer, immediately.
- SolarWinds Advisory & Patch Download
- If patching is not immediately possible:
- Restrict network access to the Web Help Desk server.
- Monitor for suspicious activity, including unexpected process execution and outbound connections.
- Audit and Monitor:
- Review logs for signs of exploitation attempts.
- Implement additional endpoint detection and response (EDR) monitoring for anomalous behavior.
NetSPI Product and Services Coverage
NetSPI’s External Attack Surface Management is issuing a version-based detection for this CVE, which will present as: Vulnerable Version – SolarWinds Web Help Desk Insecure Deserialization (CVE-2025-26399).
NetSPI’s Penetration Testing Services can also help identify exposure to this vulnerability.
Explore More Blog Posts
Anthropic’s Mythos Announcement: What it Means for Security Teams
Anthropic's Mythos accelerates automated vulnerability discovery. Read how to mitigate risk with custom benchmarks and human verification in your workflows.
Regulatory-Ready Security: Ensuring FCC Compliance for Routers
Last week, the FCC released a major update to the “Covered List”, officially adding foreign-produced consumer-grade routers to the registry of equipment deemed a threat to national security. This declaration was in part due to the discovery of backdoors in select routers that used standard apps in an attack chain to create a backdoor into seemingly protected networks.
CVE-2026-35616 & CVE-2026-21643 – Fortinet FortiClientEMS: Overview & Takeaways
Fortinet has disclosed two critical vulnerabilities in FortiClient Endpoint Management Server (EMS) that are both under active exploitation in the wild.