SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability (CVE-2025-26399)
Severity: critical · Patch status: patched · Since 2026-03-09 · CVE-2025-26399
SolarWinds Web Help Desk contain a deserialization of untrusted data vulnerability in AjaxProxy that could allow an attacker to run commands on the host machine. CISA added CVE-2025-26399 to its Known Exploited Vulnerabilities catalog on Mar 9, 2026, which means attackers are exploiting it in the wild. CISA reports known use in ransomware campaigns.
What to do
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- US federal agencies must remediate by Mar 12, 2026 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch
