CVE-2026-28306

SolarWinds Serv-U Privilege Escalation Vulnerability

No known exploitation. EPSS puts it in the 40th percentile. A vendor fix is available.

CVSS 3.19.1Critical EPSS percentile40th0.5% 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 you run Serv-U and identify who has Domain Administrator credentials.
Upgrade Serv-U to version 2026.3.
Restrict Domain Administrator access to only essential, trusted IT staff.
Review recent administrator-account and permission changes on the Serv-U server.

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 privilege escalation vulnerability that allows a domain administrator to elevate their privileges to a system administrator. The impact is lower in Windows deployments.

In plain language

Written by AI from the record

This is a serious Serv-U flaw, but it mainly affects businesses where an attacker already has Domain Administrator access.

CVE-2026-28306 is a network-accessible improper-access-control vulnerability in SolarWinds Serv-U that lets an authenticated Domain Administrator elevate to full system administration.

If you're affected

Full server takeover
System management takeover
Data exposure
Service disruption

What is it

This flaw can let someone who already has a powerful network administrator account take complete control of the server running Serv-U. It is like a person with a master key using a hidden door to take over the whole building's control room.

Who is affected

This matters if you run Serv-U on a networked server and grant Domain Administrator access to staff or service accounts. It is only a risk if an attacker already has Domain Administrator credentials on that networked Serv-U deployment.

How urgent is it

An attacker who already holds Domain Administrator credentials can use this to gain full control of the affected server. Treat this as urgent and move to the vendor's corrected release as soon as practical; no confirmed real-world exploitation has been reported.

What to do — in detail

Confirm the installed Serv-U version and determine whether the server is part of a networked deployment with Domain Administrator accounts able to access it. Upgrade to Serv-U 2026.3, following SolarWinds' release notes and normal change-control process; the findings provide no branch-specific alternatives or breaking-change notice.

If the upgrade must wait, remove unnecessary Domain Administrator access, use separate restricted accounts for routine administration, and limit network access to the Serv-U server. Review Domain Administrator sign-ins and unexpected Serv-U or server-level administrator permission changes. This CVE is not in CISA KEV, so there is no CISA remediation due date.

Technical context

CVE-2026-28306 has CVSS 9.1 (Critical) and is categorized as CWE-284, improper access control. The attack vector is network-based, requires High Privileges, requires no user interaction, and allows scope-changing compromise with high confidentiality, integrity, and availability impact. The documented precondition is existing Domain Administrator credentials on a networked SolarWinds Serv-U deployment; it is not reachable in the default configuration. CISA KEV does not list this CVE, no public exploit code is on record, and no clear dated exploitation claim was found. EPSS is 0.5% (41st percentile) with a flat trend.

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.

EPSS40th

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

0.5% chance of exploitation activity in the next 30 days, which ranks it in the 40th percentile of scored CVEs.

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

Lifecycle

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

2026-07-24OpenVAS check addedpatch available, patch available, record updated, record updated
2026-07-22Patch availablerecord updated
2026-07-21Patch availablepatch available, published, weakness classified, record updated

Affected products

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

And 1 more affected product. See all after sign-in

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

⚡ Weekly Recap: Cisco 0-Day, AI Agent RCE, ClickFix Attacks, ClickFix Surge, and Browser HijacksThe Hacker News · 2026-09-21

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