CVE-2025-26399

SolarWinds Web Help Desk Deserialization of Untrusted Data

9.8 CRITICALActively exploited (CISA KEV)Used in ransomwareEPSS 89.5%

Published23 Sept 2025
Added to CISA KEV9 Mar 2026
Remediation due12 Mar 2026

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

SolarWinds Web Help Desk≤ 12.8.6 · 12.8.7

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

Patch & vendor advisories

https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-26399

References

https://documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_12-8-7-hotfix-1_release_notes.htmRelease Notes
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-26399US Government Resource
https://www.microsoft.com/en-us/security/blog/2026/02/06/active-exploitation-solarwinds-web-help-desk/Third Party Advisory
https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-26399PatchVendor Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2025-26399 being actively exploited?

Yes. CVE-2025-26399 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 9 Mar 2026. It has been used in ransomware campaigns.

How severe is CVE-2025-26399?

CVE-2025-26399 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 89.5% probability of exploitation.

Which products are affected by CVE-2025-26399?

Affected products include SolarWinds Web Help Desk.

How do I fix CVE-2025-26399?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-26399 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.