Threats / SolarWinds / CVE-2025-40551
CVE-2025-40551
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
SolarWinds Web Help Desk vulnerability
SolarWinds Web Help Desk contains a deserialization vulnerability allowing unauthenticated remote code execution on affected hosts.
Verdict
Today item — known-exploited.
An attacker can exploit unsafe deserialization of untrusted data in Web Help Desk to execute arbitrary commands without authentication. Active exploitation in the wild increases risk.
CISA KEV Yes · 2026-02-035EPSS 0.83622 (verify live)6CVSS 9.83CISA SSVC Exploitation: active · Automatable: yes · Impact: total4Exploit Weaponized · public exploit · Metasploit module · nuclei template13
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
4 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-02-03).
Probability (EPSS)
EPSS 0.83622 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) · Affected: SolarWinds, Web Help Desk. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-502 Deserialization of Untrusted Data — weakness family: Injection.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 6 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a functional/weaponized public exploit). Catalog entries: Metasploit module, nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious serialized object and send it to the Web Help Desk application without credentials.
Business
The organization's Help Desk system is exposed to attack from any network-connected user.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
The application deserializes my untrusted payload, instantiating malicious code during object reconstruction.
Business
Deserialization flaws bypass application logic and security controls designed for normal operation.
3
Lateral reach — past segmentation narrative 3
Attacker
My payload executes arbitrary commands with the privileges of the Web Help Desk process on the host.
Business
The attacker gains direct command execution on critical support infrastructure.
4
Data at risk — exfiltration narrative 4
Attacker
I establish persistence, exfiltrate data, or pivot to other systems on the network.
Business
The breach expands beyond Help Desk to compromise customer data, internal systems, and business continuity.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by SolarWindsCNA
Credited with finding itJimi Sebree working with Horizon3.aireporter