CVE-2025-26399
CriticalExploitedPublic exploitSolarWinds 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.
Published Sep 23, 2025 · Updated Oct 11, 2026 · Also known as TR-25-0290
Key Facts
Patch immediately- CVE-2025-26399 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Web Help Desk (Solarwinds).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jan 20, 2026 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 90% probability of exploitation in the next 30 days.
- Fixed versions are available, including Web Help Desk 12.8.6.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
90%
Higher than 99.7% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 9, 2026 | Mar 12, 2026 | Known |
| Industry KEV feed | Jan 20, 2026 | Mar 12, 2026 | Known |
| CIRCL KEV | Mar 9, 2026 | Mar 12, 2026 | Not reported |
| ENISA EUVD | Mar 9, 2026 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Web Help DeskSolarwinds | 12.8.7, >= 12.8.7 and below | 12.8.6 |
Patched Releases
Web Help Desk
12.8.6
Timeline
Publicly disclosed
Sep 23, 2025
Added to Industry KEV feed
Jan 20, 2026
Added to CISA KEV
Mar 9, 2026
Added to CIRCL KEV
Mar 9, 2026
Added to ENISA EUVD
Mar 9, 2026
Last updated
Oct 11, 2026
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2025-26399
- advisoryhttps://www.microsoft.com/en-us/security/blog/2026/02/06/active-exploitation-solarwinds-web-help-desk/
- advisoryUSOM advisory
- patchhttps://www.solarwinds.com/trust-center/security-advisories/CVE-2025-26399
- exploitVulnCheck exploitation report
FAQ
Common Questions.
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.
Affected: Web Help Desk (Solarwinds) versions 12.8.7, >= 12.8.7 and below. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jan 20, 2026 and is known to be used in ransomware campaigns.
Yes. It was added on Mar 9, 2026 with a federal remediation due date of Mar 12, 2026.
Public exploit code is available.
Fixed versions are available, including Web Help Desk 12.8.6.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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