SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability
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…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 5 / 5
- KEV catalog (CISA)09 Mar 2026
- Exploited in EUVD (ENISA)09 Mar 2026
- Used by ransomwareyes
- EPSS above 10 %90.6%
- No account, over the networkyes
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
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.
Affected products
- 12.8.7 and below
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
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Published
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Exploitation reported (ENISA)
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Added to the KEV catalog
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CISA remediation due date
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EPSS peak: 90.6%
References
Other exploited vulnerabilities from the same vendor
- CVE-2026-28318SolarWinds Serv-U Uncontrolled Resource Consumption Vulnerability6.7 · Actively exploited
- CVE-2025-40536SolarWinds Web Help Desk Security Control Bypass Vulnerability7.8 · Background exploitation
- CVE-2025-40551SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability8.8 · Background exploitation
- CVE-2024-28987SolarWinds Web Help Desk Hardcoded Credential Vulnerability8.8 · Background exploitation
- CVE-2024-28986SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability8.9 · Background exploitation
- CVE-2024-28995SolarWinds Serv-U Path Traversal Vulnerability8.8 · Background exploitation