---
title: "CVE-2025-40551: SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-40551/
description: "CVE-2025-40551 (SolarWinds Web Help Desk): Exploited in the wild (CISA KEV). SolarWinds Web Help Desk was found to be susceptible to an untrusted data…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-01-28
date_modified: 2026-10-07
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-40551"
kev: true
cvss: 9.8
epss: 0.84181
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-40551: SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run SolarWinds Web Help Desk. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-02-03, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-02-06 ; treat that as the outer limit, not the target.
- EPSS 84.2% , percentile 99.7: FIRST’s model estimates a 84.2% chance of exploitation activity in the next 30 days, higher than 99.7% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it is

SolarWinds Web Help Desk was found to be susceptible to an untrusted data deserialization vulnerability that could lead to remote code execution, which would allow an attacker to run commands on the host machine. This could be exploited without authentication.

## Affected products (CVE record)

- SolarWinds Web Help Desk: 12.8.8 HF1 and below

## Severity

- SolarWinds CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2026-02-03; federal due date 2026-02-06. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 84.18% probability of exploitation activity in the next 30 days; percentile 99.7.

## Sources

- [solarwinds.com](https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-40551)
- [documentation.solarwinds.com](https://documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_2026-1_release_notes.htm)
- [Listed in CISA KEV notes (solarwinds.com)](https://www.solarwinds.com/trust-center/security-advisories/cve-2025-40551)
- [CVE.org record CVE-2025-40551](https://www.cve.org/CVERecord?id=CVE-2025-40551)
- [NVD entry CVE-2025-40551](https://nvd.nist.gov/vuln/detail/CVE-2025-40551)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-40551)

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Source page: https://erroneo.us/security/cve/CVE-2025-40551/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt