---
id: CVE-2026-28318
title: SolarWinds Serv-U Unauthenticated Denial of Service Vulnerability
summary: >-
  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 Tru…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-400
vendor: SolarWinds
product: Serv-U
affected:
  - Serv-U <= 15.5.4
ssvc:
  exploitation: active
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-06-05T00:00:00+00:00'
exploited: true
exploitAvailable: true
published: '2026-06-04'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T10:29:06.114Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-28318'
references:
  - url: 'https://www.solarwinds.com/trust-center/security-advisories/CVE-2026-28318'
  - url: >-
      https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-5-4-hotfix-1_release_notes.htm
tags:
  - cve.org
  - in-the-wild
  - exploit-available
  - kev
epss: 0.01942
epssPercentile: 0.79863
kev: true
kevDateAdded: '2026-06-05'
kevDueDate: '2026-06-19'
kevRansomware: false
exploits:
  github: 2
  githubRepos:
    - 'https://github.com/EaEa0001/servu-cve-2026-28318-poc'
    - 'https://github.com/BishopFox/CVE-2026-28318-check'
  checkedAt: '2026-10-21T10:46:59.308Z'
zeroDay: true
ingestedAt: '2026-10-21T10:46:55.413Z'
---

## Overview

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

- `Serv-U <= 15.5.4`

## Remediation

Upgrade to SolarWinds Serv-U 15.5.4 Hotfix 1. Use the mitigation steps until the upgrade is possible.

### Workarounds

Block any POST requests containing 'Content-Encoding: deflate'. This function is not required for SolarWinds Serv-U.