CVE-2025-26399
Published: April 11, 2026
Official Description
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.
Technical Analysis
CVE-2025-26399 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2025-26399 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Exploit & PoC Resources
News & Research Mentioning CVE-2025-26399
The Cybersecurity and Infrastructure Security Agency (CISA) gave all federal civilian agencies until Thursday to patch CVE-2025-26399 — a critical vulnerability impacting the popular SolarWinds Web Help Desk. [xlite_meta score:62 src:The Record xlite_fp:f074f90e4292864e01251887955142a64a47a10793c24432d8cb88c987221552]
CISA has added three new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2021-22054 Omnissa Workspace ONE Server-Side Request Forgery CVE-2025-26399 SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability CVE-2026-1603 Ivanti Endpoint Manager (EPM) Authentication Bypass Vulnerability These types of vulnerabilities are frequent attack vectors for malicious cyber actors and pose significant risks to the federal enterprise. Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities established the KEV Catalog as a living list of known Common Vulnerabilities and Exposures (CVEs) that carry significant risk to the federal e [xlite_meta score:54 src:CISA Alerts xlite_fp:e0c5e5fb15f9367431feea5b82cada21d0f5c8efe863e9b56a6a091f68332f66]
Huntress has observed active exploitation of a deserialization and remote code execution against the SolarWinds Web Help Desk software (CVE-2025-26399). [xlite_meta score:37 src:Huntress Blog xlite_fp:19734d20fb1c03cd9eec100a94587aa873e5102bad12ea596c111c9525dc9a2d]
Quick Facts
Known Threat Actors
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2025-26399 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1