SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2026-03-09
• Known to be used in ransomware campaigns
• EPSS: 90% chance of exploitation in the next 30 days (higher than 100% of CVEs)
• Critical severity: CVSS 9.8

[ Description ]Official description

SolarWinds Web Help Desk was found to be susceptible to an unauthenticated AjaxProxy deserialization remote code execution vulnerability that, if exploited, would allow an attacker to run commands on the host machine. This vulnerability is a patch bypass of CVE-2024-28988, which in turn is a patch bypass of CVE-2024-28986.

CISA: 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.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 12 Mar 2026): Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

• Patch on solarwinds.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ References ]References

• documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_12-8-7-hot…Release Notes
• www.solarwinds.com/trust-center/security-advisories/CVE-2025-26399PatchVendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource
• www.microsoft.com/en-us/security/blog/2026/02/06/active-exploitation-solarwinds-web-hel…Third Party Advisory