CVE-2025-26399: CWE-502: Deserialization of Untrusted Data in SolarWinds Web Help Desk
A threat actor compromised three web servers hosting recreation management software for municipalities and parks organizations by exploiting a file upload vulnerability. After multiple failed exploitation attempts, the attacker registered legitimate accounts and abused the member file upload function to deploy webshells. The attacker enumerated systems, extracted database credentials, and targeted payment card data from Fortis webhook logs. User-agent strings indicate Chinese origin, with suspected AI-generated scripts throughout the operation. The adversary adapted tactics across compromises, employing timestomping and file masquerading for defense evasion. When one server returned to production prematurely, the attacker injected a trojanized jQuery file into authentication pages, establishing WebRTC and WebSocket channels for credential harvesting via Cloudflare Workers infrastructure.
AI Analysis
Technical Summary
SolarWinds Web Help Desk versions up to 12.8.7 are vulnerable to an unauthenticated remote code execution vulnerability due to insecure deserialization in the AjaxProxy component. This vulnerability (CVE-2025-26399) allows attackers to execute arbitrary commands on the host system without authentication. It is a patch bypass of earlier vulnerabilities CVE-2024-28988 and CVE-2024-28986, indicating that previous fixes were circumvented. The vulnerability has a CVSS 3.1 base score of 9.8, reflecting network attack vector, low complexity, no privileges required, no user interaction, and full impact on confidentiality, integrity, and availability.
Potential Impact
Successful exploitation allows an unauthenticated attacker to execute arbitrary code on the host running SolarWinds Web Help Desk, potentially leading to full system compromise. The vulnerability affects confidentiality, integrity, and availability of the affected system. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since this vulnerability is a patch bypass of previous CVEs, it is critical to monitor SolarWinds advisories for an official fix. Until a patch is available, restrict access to the Web Help Desk interface and consider additional network-level protections to limit exposure.
Indicators of Compromise
- cve: CVE-2025-26399
- hash: 0d8f7bf30aa1ac95d59fed24c433dd2b3d57767f38c088721699c841c6e861d3
- hash: 0d93c3a8ded46887f79ac4ca7f238c458de2231243176f6c05062e34f238d19a
- hash: 5f69ff7a2e024f94cc5f816fa16c90054b09d9ac430b1f8b0631dfdd4472905e
- hash: 7bb594a77f726bf21a49f717024f2915f82f47eb623d2ad305259301de1f1ab4
- hash: b06b581d91f4108900d188c3ee1af18502a8cb65d4e101663b791bd670867485
- hash: e9dee286069afb6b411febb96b91a963cd16baffbf8b6aa951e0ef1a7e0e3879
CVE-2025-26399: CWE-502: Deserialization of Untrusted Data in SolarWinds Web Help Desk
Description
A threat actor compromised three web servers hosting recreation management software for municipalities and parks organizations by exploiting a file upload vulnerability. After multiple failed exploitation attempts, the attacker registered legitimate accounts and abused the member file upload function to deploy webshells. The attacker enumerated systems, extracted database credentials, and targeted payment card data from Fortis webhook logs. User-agent strings indicate Chinese origin, with suspected AI-generated scripts throughout the operation. The adversary adapted tactics across compromises, employing timestomping and file masquerading for defense evasion. When one server returned to production prematurely, the attacker injected a trojanized jQuery file into authentication pages, establishing WebRTC and WebSocket channels for credential harvesting via Cloudflare Workers infrastructure.
CVSS v3.1
Score 9.8critical
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
SolarWinds Web Help Desk versions up to 12.8.7 are vulnerable to an unauthenticated remote code execution vulnerability due to insecure deserialization in the AjaxProxy component. This vulnerability (CVE-2025-26399) allows attackers to execute arbitrary commands on the host system without authentication. It is a patch bypass of earlier vulnerabilities CVE-2024-28988 and CVE-2024-28986, indicating that previous fixes were circumvented. The vulnerability has a CVSS 3.1 base score of 9.8, reflecting network attack vector, low complexity, no privileges required, no user interaction, and full impact on confidentiality, integrity, and availability.
Potential Impact
Successful exploitation allows an unauthenticated attacker to execute arbitrary code on the host running SolarWinds Web Help Desk, potentially leading to full system compromise. The vulnerability affects confidentiality, integrity, and availability of the affected system. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since this vulnerability is a patch bypass of previous CVEs, it is critical to monitor SolarWinds advisories for an official fix. Until a patch is available, restrict access to the Web Help Desk interface and consider additional network-level protections to limit exposure.
Technical Details
- Data Version
- 5.1
- Assigner Short Name
- SolarWinds
- Date Reserved
- 2025-02-08T00:19:09.395Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Indicators of Compromise
Cve
| Value | Description | Copy |
|---|---|---|
cveCVE-2025-26399 | — |
Hash
| Value | Description | Copy |
|---|---|---|
hash0d8f7bf30aa1ac95d59fed24c433dd2b3d57767f38c088721699c841c6e861d3 | — | |
hash0d93c3a8ded46887f79ac4ca7f238c458de2231243176f6c05062e34f238d19a | — | |
hash5f69ff7a2e024f94cc5f816fa16c90054b09d9ac430b1f8b0631dfdd4472905e | — | |
hash7bb594a77f726bf21a49f717024f2915f82f47eb623d2ad305259301de1f1ab4 | — | |
hashb06b581d91f4108900d188c3ee1af18502a8cb65d4e101663b791bd670867485 | — | |
hashe9dee286069afb6b411febb96b91a963cd16baffbf8b6aa951e0ef1a7e0e3879 | — |
Threat ID: 68d22c2079681e6adcf142e8
Added to database: 09/23/2025, 05:12:00 UTC
Last enriched: 08/04/2026, 13:22:15 UTC
Last updated: 10/03/2026, 16:22:48 UTC
Views: 776
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