CVE-2025-26399

SolarWinds Web Help Desk Deserialization of Untrusted Data Privilege Escalation Vulnerability

9.8 CriticalIn KEVPublic exploit

SolarWinds Web Help Desk was found to be susceptible to an unauthenticated AjaxProxy deserialization remote code execution vulnerability that, if exploited, would allow an attacker to run commands on the host machine. This vulnerability is a patch bypass of CVE-2024-28988, which in turn is a patch bypass of CVE-2024-28986.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

90.6%Up 90.4 points since Sep 23, 2025

What each source reports

CVE List Score used 9.8

SolarWinds Web Help Desk Deserialization of Untrusted Data Privilege Escalation Vulnerability

Record: CVE-2025-26399
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-502
Updated: 2026-11-02

EUVDEUVD-2025-30842 9.8

Record: EUVD-2025-30842
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-vfrj-f292-3f24 9.8

SolarWinds Web Help Desk was found to be susceptible to an unauthenticated AjaxProxy...

Record: GHSA-vfrj-f292-3f24
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-502
Updated: 2026-11-02

CISA KEV No score

SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability

SolarWinds Web Help Desk contain a deserialization of untrusted data vulnerability in AjaxProxy that could allow an attacker to run commands on the host machine.

Record: CVE-2025-26399
Weakness: CWE-502
Updated: 2026-11-02

NVD 9.8

Record: CVE-2025-26399
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-502
Updated: 2026-11-02

Affected products

solarwinds web help desk

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
PoC in GitHub	rxerium/CVE-2025-26399	2025-09-23
Nuclei	SolarWinds Web Help Desk < 12.8.7 - AjaxProxy Deserialization RCE

History

History
Recorded	Changed	Sources
Nov 3, 2026	exploitation, exploits
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, CISA KEV, Nuclei, NVD, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2025-26399 is a critical vulnerability (CVSS 9.8) in Solarwinds Web Help Desk, published September 23, 2025. CISA lists it as known to be exploited, since March 9, 2026. EUVD reports exploitation since March 9, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 90.6%, the 99th percentile. No source names a fixed version.