SolarWinds · Serv-U
CVE-2026-28318
SolarWinds Serv-U Unauthenticated Denial of Service Vulnerability
What it is
SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate. Mitigation steps are provided to secure customer environments in the SolarWinds Trust Center if you are unable to deploy the update
CISA: SolarWinds Serv-U contains an uncontrolled resource consumption vulnerability that allows specially crafted POST requests using the Content-Encoding: deflate header to crash the Serv-U service without authentication.
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.
Deadline for US federal agencies: June 19, 2026
More exploited flaws from SolarWinds
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Jul 17, 2024 | Path Traversal Vulnerability | Serv-U | High 8.6 | 99.6% |
| Jan 21, 2022 | Improper Input Validation | Serv-U | Medium 4.3 | 3.5% |
| Nov 3, 2021 | Remote Code Execution | Serv-U | Critical 9.0 | 91% |
| Mar 9, 2026 | Deserialization of Untrusted Data | Web Help Desk | Critical 9.8 | 90% |
| Feb 12, 2026 | Security Control Bypass | Web Help Desk | High 8.1 | 74% |
| Feb 3, 2026 | Deserialization of Untrusted Data | Web Help Desk | Critical 9.8 | 84% |
| Oct 15, 2024 | Hardcoded Credential | Web Help Desk | Critical 9.1 | 93% |
| Aug 15, 2024 | Deserialization of Untrusted Data | Web Help Desk | Critical 9.8 | 85% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.