Serv UApplication · Solarwinds

CVE-2025-40549

CRITICAL · 9.1 CVSS v3.1 Published 2025-11-18
Fix available
A fix is available. Upgrade to 15.5.3 or later.
See remediation →
97/100
Remediation priority · Urgent
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A Path Restriction Bypass vulnerability exists in Serv-U that when abused, could give a malicious actor with access to admin privileges the ability to execute code on a directory. This issue requires administrative privileges to abuse. On Windows systems, this scored as medium due to differences in how paths and home directories are handled.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-22

A file path is built from user input without being confined, so sequences like “../” let an attacker step outside the intended directory. That can expose configuration, credentials, or source code, and in the worst case lets an attacker write files where they shouldn't. A durable fix resolves and canonicalises the path, then rejects anything that escapes a known-safe base directory.

General guidance for the path traversal class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Serv UApplication
Affected:< 15.5.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 15.5.3 or later
Fixed in 15.5.3
Vendor patch www.solarwinds.com →
Recommended fix High confidence

Serv-U 15.5.3

  1. 1. Identify the current Serv-U installation version by checking the Serv-U admin console or using the version check command
  2. 2. Navigate to the SolarWinds trust center security advisory page for CVE-2025-40549 to obtain the official patch and release notes
  3. 3. Download the Serv-U version 15.5.3 (or latest patched version) from the official SolarWinds download portal
  4. 4. Create a complete backup of the current Serv-U configuration, including all user settings, virtual folders, and security configurations
  5. 5. Review the release notes to verify no incompatible changes affect your specific deployment configuration
  6. 6. Stop the Serv-U service before applying the upgrade to prevent data corruption
  7. 7. Apply the upgrade by running the installer for version 15.5.3 on the target server
  8. 8. After installation completes, verify the new version is 15.5.3 or higher
Caveat Security fix upgrade with minimal expected breaking changes; verify custom configurations against release notes

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $2,300. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-40549 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-40549 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data