CVE-2026-28304Network attack vector

Authenticated root-level remote code execution

Published Jul 21, 2026 · Updated Jul 21, 2026

Improper access control in SolarWinds Serv-U 15.5.4 HF1 and earlier allows remote authenticated users to execute code as root. SolarWinds has not disclosed the affected component or the access-control operation that enables execution. Exploitation requires high privileges over a network; Linux execution reaches root, while SolarWinds reports lower impact on Windows.

CVSS severity9.1
Critical
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in SolarWinds Serv-U 15.5.4 HF1 and earlier allows remote authenticated users to execute code as root. SolarWinds has not disclosed the affected component or the access-control operation that enables execution. Exploitation requires high privileges over a network; Linux execution reaches root, while SolarWinds reports lower impact on Windows.

The record

CVE
CVE-2026-28304
Published
Jul 21, 2026
Updated
Jul 21, 2026
Vendor
SolarWinds
Product
Serv-U
Classifications
CWE-284, CAPEC-233, T1068
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=15.5.4 HF1 and below

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

SolarWinds · Serv-Uversion=15.5.4 HF1 and below

Published CVSS scores

4.7SolarWindsCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
9.1SolarWindsCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
CAPEC-233Privilege Escalation
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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