# CVE-2026-28304: SolarWinds Serv-U remote code execution via improper access control

Source: https://junglewise.ai/threats/cve-2026-28304-solarwinds-serv-u-remote-code-execution-via-improper-access  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-21. Updated: 2026-07-21  
License: CC BY 4.0 with a link back

CVE-2026-28304 · Severity: critical · CVSS 9.1 · Published 2026-07-21

SolarWinds Serv-U, a managed file transfer and FTP server, is affected by a critical security vulnerability. An attacker could exploit this flaw to remotely execute arbitrary commands on the server with high privileges (root). This could lead to a complete takeover of the file transfer system, unauthorized access to sensitive customer data, and potential disruption of business operations.

Technologies: [SolarWinds Serv-U](https://junglewise.ai/threats/technologies/serv-u). Vendors: [SolarWinds](https://junglewise.ai/threats/vendors/solarwinds).

## Quick answers

**Is CVE-2026-28304 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-28304 being exploited in the wild.

**How severe is CVE-2026-28304?** Critical severity, with a CVSS score of 9.1, published 21 July 2026.

**Which products and versions are affected?** SolarWinds Serv-U 15.5.4 HF1 and below.

**Is there a fix for CVE-2026-28304?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-28304 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-28304?** Check whether you run SolarWinds Serv-U at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

SolarWinds Serv-U is vulnerable to remote code execution (RCE) due to improper access control (CWE-284). The vulnerability allows an authenticated attacker with high privileges to execute arbitrary code on the host system. On non-Windows deployments, this execution occurs with root privileges, while the impact is reportedly lower on Windows systems. The attack vector is network-based and does not require user interaction, though it does require high-level administrative credentials. SolarWinds has addressed this issue in Serv-U version 2026.3.

## Affected products

- SolarWinds Serv-U 15.5.4 HF1 and below

## Timeline

- 2026-07-21: disclosed
- 2026-07-21: advisory

## References

- [https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_2026-3_release_notes.htm](https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_2026-3_release_notes.htm)
- [https://www.solarwinds.com/trust-center/security-advisories/CVE-2026-28304](https://www.solarwinds.com/trust-center/security-advisories/CVE-2026-28304)

## Related threats

- [SolarWinds Serv-U broken access control privilege escalation](https://junglewise.ai/threats/cve-2026-28321-solarwinds-serv-u-broken-access-control-privilege-escalation)
- [SolarWinds Serv-U privilege escalation via IDOR](https://junglewise.ai/threats/cve-2026-28317-solarwinds-serv-u-privilege-escalation-via-idor)
- [SolarWinds Serv-U IDOR privilege escalation to root](https://junglewise.ai/threats/cve-2026-28316-solarwinds-serv-u-idor-privilege-escalation-to-root)
- [SolarWinds Serv-U stored XSS in administrator interface](https://junglewise.ai/threats/cve-2026-28315-solarwinds-serv-u-stored-xss-in-administrator-interface)
- [SolarWinds Serv-U account takeover via IDOR](https://junglewise.ai/threats/cve-2026-28314-solarwinds-serv-u-account-takeover-via-idor)