CVE-2025-26399
SolarWinds Web Help Desk Deserialization of Untrusted Data Privilege Escalation Vulnerability
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.
- Severity
- 9.8 CriticalCVSS 3.1, CVE List
- Exploit chance
- 90.6%EPSS, 99th percentile
- Exploitation
- ExploitedCISA KEV,
- Fixed in
- No fix listedNo source names one
Description
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
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | rxerium/CVE-2025-26399 | 2025-09-23 |
| Nuclei | SolarWinds Web Help Desk < 12.8.7 - AjaxProxy Deserialization RCE |
What each source reports
CVE List Score used
SolarWinds Web Help Desk Deserialization of Untrusted Data Privilege Escalation Vulnerability
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.
- Record
CVE-2025-26399- CVSS 3.1
- 9.8 Critical
CVSS: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
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.
- Record
EUVD-2025-30842- CVSS 3.1
- 9.8 Critical
CVSS: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
SolarWinds Web Help Desk was found to be susceptible to an unauthenticated AjaxProxy...
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.
- Record
GHSA-vfrj-f292-3f24- CVSS 3.1
- 9.8 Critical
CVSS: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 KEVNo 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
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.
- Record
CVE-2025-26399- CVSS 3.1
- 9.8 Critical
CVSS: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
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation, exploits | ||
| 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.
References
solarwinds.com/trust-center/security-advisories/CVE-2025-26399
documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_12-8-7-hotfix-1_release_notes.htm
microsoft.com/en-us/security/blog/2026/02/06/active-exploitation-solarwinds-web-help-desk
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-26399
nvd.nist.gov/vuln/detail/CVE-2025-26399
github.com/advisories/GHSA-vfrj-f292-3f24