CVE-2025-26399 — SolarWinds Web Help Desk Deserialization of Untrusted Data 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

01What is this 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.

02Affected products

Vendor	Product	Versions
SolarWinds	Web Help Desk	12.8.7 and below

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2026-03-09. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

08Timeline

• Published: 2025-09-23T05:07:14.702Z
• Last modified: 2026-03-10T03:55:22.393Z
• Added to CISA KEV: 2026-03-09
• BOD 22-01 due: 2026-03-12

09References

• www.solarwinds.com — https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-26399
• documentation.solarwinds.com — https://documentation.solarwinds.com/en/success_center/whd/content/release_notes…