CVE entry · CVE-2025-26399
CVE-2025-26399: SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability
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.
- Actively exploited: added to CISA’s KEV catalog on March 9, 2026.
- Used by ransomware, according to CISA.
- Remediation deadline for US federal agencies: March 12, 2026.
Description from CISA’s KEV catalog.
What to do
- Check whether your estate includes SolarWinds Web Help Desk, including internet-facing devices.
- Apply the vendor’s patch or mitigations (references below). Failing that, isolate the product or stop using it, as CISA requires of US federal agencies.
- An exploited vulnerability has often been used before it was fixed: look for signs of compromise, especially on internet-facing devices.
References
- Vendor advisory or reference cited by CISA (www.solarwinds.com)
- Vendor advisory or reference cited by CISA (documentation.solarwinds.com)
- NVD entry (NIST)
- CISA KEV catalog