CVE-2025-40539
Serv-U type confusion allows privileged native code execution.
Is CVE-2025-40539 being exploited?
Not confirmed. CVE-2025-40539 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.45% probability of exploitation in the next 30 days.
How severe is CVE-2025-40539?
CVE-2025-40539 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2025-40539?
Yes. A fix has been recorded for CVE-2025-40539. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2025-40539 affect?
CVE-2025-40539 affects SolarWinds Serv-U File Transfer Server. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2025-40539?
Patch when available; limit admin rights; monitor privilege activity.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Admin-authenticated attacker can execute native code with elevated privileges on the Serv-U host, potentially full server takeover.
Patch when possible
- affectedSolarWinds Serv-U 15.5.3 and prior versions
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.