Root code execution via arbitrary file writes
Published Jul 21, 2026 · Updated Jul 21, 2026
Broken access control in SolarWinds Serv-U 15.5.4 HF1 and earlier allows remote authenticated users to read or write arbitrary files. SolarWinds has not disclosed the affected request handler or the missing authorization check that permits access outside the administrator's intended scope. Domain administrator access is required; on Linux, file writes support privilege escalation and code execution as root, while Windows impact is lower.
Summary
What happened
Broken access control in SolarWinds Serv-U 15.5.4 HF1 and earlier allows remote authenticated users to read or write arbitrary files. SolarWinds has not disclosed the affected request handler or the missing authorization check that permits access outside the administrator's intended scope. Domain administrator access is required; on Linux, file writes support privilege escalation and code execution as root, while Windows impact is lower.
The record
- CVE
- CVE-2026-28321
- Published
- Jul 21, 2026
- Updated
- Jul 21, 2026
- Vendor
- SolarWinds
- Product
- Serv-U
- Classifications
- CWE-284, CAPEC-126, CAPEC-242, CAPEC-1, T1068
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Jul 21, 2026CVE publishedPublication date reported by the CVE source.
- Jul 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=15.5.4 HF1 and below
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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