CVE-2025-40539: SolarWinds Serv-U · Incorrect Type Conversion or Cast
Affects SolarWinds Serv-USource CVE Database V5
Not known to be exploited · CVSS 9.1 Critical.
Data as of 29 Oct 2026, 19:04 UTC
Contested
Critical score, yet low EPSS after six months- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| SolarWindsServ-U | Affected
| Fixed in– |
AI-suggested
Until a patch is released, restrict administrative access to Serv-U servers to trusted personnel only and enforce strong authentication and access controls. Review and harden service account permissions, especially on Windows, to ensure Serv-U services run with the least privileges necessary. Implement network segmentation to limit exposure of Serv-U servers to untrusted networks. Monitor logs for unusual administrative activity or signs of privilege escalation attempts. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and block unauthorized code execution. Conduct regular vulnerability assessments and penetration testing focused on privilege escalation vectors. Finally, maintain an incident response plan that includes procedures for handling potential exploitation of this vulnerability.
Description
A type confusion vulnerability exists in Serv-U which when exploited, gives a malicious actor the ability to execute arbitrary native code as privileged account. This issue requires administrative privileges to abuse. On Windows deployments, the risk is scored as a medium because services frequently run under less-privileged service accounts by default.