Critical Access control

CVE-2026-28316 — SolarWinds Serv-U Insecure Direct Object Reference (IDOR) Vulnerability

SolarWinds Serv-U is affected by an insecure direct object reference (IDOR) vulnerability that can lead to privilege escalation to a system administrator with the ability to execute commands as the root user. This issue requires a domain account with administrator access. The impact is lower in Windows deployments.

Published Jul 21, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: SolarWinds

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

Solarwinds

Serv-u

CVSS base

9.1

Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Solarwinds Serv-u).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Solarwinds	Serv-u	< 2026.3	Vulnerable	NIST National Vulnerability Database
Solarwinds	Serv-u	version 15.5.4 HF1 and below	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

High

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.1	CVSS 3.1	Critical	2.3	6.0	psirt@solarwinds.com via NIST National Vulnerability Database
9.1	CVSS 3.1	Critical	—	—	SolarWinds via CVE Program (cve.org) e CISA ADP
4.7	CVSS 3.1	Medium	—	—	SolarWinds via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H (score shown at the top: psirt@solarwinds.com)

Sources assign different scores within the same severity band. For prioritization we use 9.1 (psirt@solarwinds.com via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-639 · Authorization Bypass Through User-Controlled Key (IDOR)

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Audit administrative actions and access to resources outside each user’s normal pattern.

web/proxy/WAF logsnetwork IDS/IPSauthentication logsapplication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · solarwinds/serv-u
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 9.1
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Jul 21, 2026 · SolarWinds

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

2 on the record

documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_2026-3_release_no
Release Notes, Vendor Advisory, release-notes, NIST National Vulnerability Database
www.solarwinds.com/trust-center/security-advisories/CVE-2026-28316
Vendor Advisory, vendor-advisory, NIST National Vulnerability Database

Elsewhere on this site

Solarwinds
every CVE for this vendor

Access control
same class

CWE-639
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-28321 SolarWinds Serv-U Broken Access Control Vulnerability Jul 21, 2026
Critical CVE-2026-28317 SolarWinds Serv-U Insecure Direct Object Reference (IDOR) Vulnerability Jul 21, 2026
Critical CVE-2026-28312 SolarWinds Serv-U Privilege Escalation Vulnerability Jul 21, 2026
Critical CVE-2026-28313 SolarWinds Serv-U Insecure Direct Object Reference (IDOR) Vulnerability Jul 21, 2026
Medium CVE-2026-28315 SolarWinds Serv-U Authenticated Stored Cross-site Scripting (XSS) Vulnerability Jul 21, 2026
Critical CVE-2026-28314 SolarWinds Serv-U Insecure Direct Object Reference (IDOR) Vulnerability Jul 21, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-28316 is "SolarWinds Serv-U Insecure Direct Object Reference (IDOR) Vulnerability", rated Critical. It affects Serv-u (Solarwinds); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.1 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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