SolarWinds Serv-U DoS via malformed Content-Encoding: deflate POST
CVE-2026-28318 Published on June 4, 2026
SolarWinds Serv-U Unauthenticated Denial of Service Vulnerability
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
Known Exploited Vulnerability
This SolarWinds Serv-U Uncontrolled Resource Consumption Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. 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.
The following remediation steps are recommended / required by June 19, 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.
Vulnerability Analysis
CVE-2026-28318 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Resource Exhaustion Vulnerability?
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
CVE-2026-28318 has been classified to as a Resource Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-28318
Want to know whenever a new CVE is published for SolarWinds Serv U? stack.watch will email you.
Affected Versions
SolarWinds Serv-U Version 15.5.4 and previous versions is affected by CVE-2026-28318Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.