CVE-2026-28304

SolarWinds Serv-U Remote Code Execution Vulnerability

No known exploitation. EPSS puts it in the 54th percentile. A vendor fix is available.

CVSS 3.19.1Critical EPSS percentile54th0.8% chance in 30 days CISA KEVNot listedNo confirmed exploitation
No public exploit known FixVendor fixNo build named by the sources

Published 2026-07-21Updated 2026-07-24Sources: CVE.org, NVD

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

Steps

Written by AI from the record

Check whether your organization runs Serv-U and identify its installed version.
Upgrade Serv-U to version 2026.3.
Review high-level Serv-U accounts and revoke access that is no longer needed.
Check Serv-U server activity for unexpected commands or account changes.

Vendor advisory Usually a quick update

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

SolarWinds Serv-U is affected by a remote code execution vulnerability that, when exploited, can allow the arbitrary execution of code remotely as root. The impact is lower in Windows deployments.

In plain language

Written by AI from the record

Businesses using Serv-U before version 2026.3 should upgrade: someone with high-level access could take over the server.

Authenticated remote code execution in SolarWinds Serv-U allows a highly privileged attacker to execute arbitrary commands as root.

If you're affected

Full server takeover
File transfer disruption
Sensitive file exposure
Ransomware risk
Service outages

What is it

This is a flaw in Serv-U that lets a person who already has powerful access run commands on the server. It is like giving someone with a master key permission to remodel the entire building, including opening locked offices and shutting down essential services.

Who is affected

This matters to you if your business runs Serv-U for file transfers. It is only a risk if an attacker already has a highly privileged Serv-U account or equivalent high-level access.

How urgent is it

An attacker who already has high-level Serv-U access can take control of the server, so treat this as urgent. Upgrade promptly and review powerful accounts, especially where those credentials may have been shared, reused, or exposed.

What to do — in detail

Confirm whether Serv-U is installed and record the running version. Systems below 2026.3 should be upgraded to Serv-U 2026.3, the vendor-fixed release.

Before upgrading, review the Serv-U 2026.3 release notes and test the upgrade in a non-production environment where practical; the provided findings do not identify any breaking-change details. If patching must be delayed, restrict and review highly privileged Serv-U accounts, remove unneeded administrative access, and limit server access to trusted administrators.

CISA has not added this CVE to the Known Exploited Vulnerabilities catalog, so there is no CISA remediation due date. After remediation, investigate unusual administrative logins, account-permission changes, and unexpected commands executed by the Serv-U service.

Technical context

CVE-2026-28304 is rated CVSS 9.1 Critical (AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H) and is associated with CWE-284. The network-reachable issue requires high privileges and no user interaction; successful exploitation enables arbitrary command execution as root. It is not listed in CISA KEV, no confirmed exploitation was reported in the supplied news findings, and no public exploit code is on record. EPSS predicts a 0.8% likelihood (54th percentile) and the trend is flat.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS54th

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.8% chance of exploitation activity in the next 30 days, which ranks it in the 54th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

10 events over 3 days, from the signal feeds we watch.

2026-07-24OpenVAS check addedpatch available, patch available, record updated, record updated
2026-07-21Patch availablepatch available, published, weakness classified, record updated

Affected products

SolarWindscommercial · USaka solar winds
- Serv-UWeb AppOn-premEnterprise Software / itsm-monitoring

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Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Scored 9.1 by NVD.

How it is reached

Attack Vector NetworkExploitable remotely over the network without any special conditions
Attack Complexity LowNo special conditions — the attack can be reliably reproduced
Privileges Required HighRequires admin or elevated privileges
User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)

Impact if exploited

Confidentiality HighTotal information disclosure — all data in the component is compromised
Integrity HighTotal loss of integrity — attacker can modify any data in the component
Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

CWE-284No name in the record

Sources

References in the record

In the news

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