Actively exploited · Published Jun 4, 2026 · Assigned by SolarWinds

CVE-2026-28318SolarWinds Serv-U Unauthenticated Denial of Service Vulnerability

High 7.5 Exploited

In plain English

A high-severity uncontrolled resource consumption in Serv-U from SolarWinds. Attackers are actively exploiting it in the wild (listed by CISA on June 5, 2026). The chance it is exploited in the next 30 days is estimated at 43.7% (higher than 99% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)43.7%top 1.3% of all CVEs
Exploited in the wildYesCISA KEV since Jun 5, 2026
Attack tooling1Public PoC

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.

Federal agencies must remediate by Jun 19, 2026.

Official description

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

Affected products (as reported)

VendorProductVersions
SolarWinds Serv-U 0 – through 15.5.4

Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References