Threats / SolarWinds / CVE-2025-26399
CVE-2025-26399
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
SolarWinds Web Help Desk vulnerability
SolarWinds Web Help Desk contains a deserialization vulnerability in AjaxProxy allowing remote code execution on affected systems.
Verdict
Today item — known-exploited.
An attacker can exploit unsafe deserialization of untrusted data in the AjaxProxy component to execute arbitrary commands with the privileges of the Web Help Desk service, potentially compromising the host system.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
6 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 2026-03-09).
Probability (EPSS)
EPSS 0.8833 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: SolarWinds, Web Help Desk. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-502 Deserialization of Untrusted Data — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
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 AjaxProxy endpoint.
Business
The organization's Web Help Desk service becomes a pivot point for lateral movement within the network.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I trigger deserialization of my payload, causing arbitrary code execution on the server.
Business
Attackers gain command execution capability within the IT support infrastructure, potentially accessing sensitive customer and employee data.
3
Lateral reach — past segmentation narrative 3
Attacker
I establish persistence and escalate privileges to move deeper into the environment.
Business
The organization faces operational disruption, data breach risk, and potential regulatory compliance violations.
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 itAnonymous working with Trend Micro Zero Day Initiativereporter