Overview
CVE-2025-26391 details a Cross-Site Scripting (XSS) vulnerability identified in the SolarWinds Observability Self-Hosted platform. This vulnerability allows attackers with low-level authenticated access to inject malicious scripts into user-created URL fields, potentially leading to unauthorized actions, data theft, or other malicious activities.
Technical Details
The vulnerability resides in the way the SolarWinds Observability platform handles user-supplied input within URL fields. Specifically, insufficient sanitization and encoding of user-provided data allows an attacker to inject malicious JavaScript code. When a user accesses a page containing the injected script, the script executes in the user’s browser, operating within the security context of the SolarWinds Observability application. This vulnerability requires authentication, however, the required privileges are relatively low, making it easier for attackers to exploit.
CVSS Analysis
The National Vulnerability Database (NVD) has assigned a CVSS v3.x score of 5.4 (Medium) to CVE-2025-26391. This score reflects the potential impact of the vulnerability. The CVSS vector likely indicates that while exploitation requires authentication, the attack complexity is low, and the potential impact on confidentiality, integrity, and availability is moderate.
Possible Impact
Successful exploitation of this XSS vulnerability could have several significant impacts:
- Account Compromise: An attacker could potentially steal user session cookies or credentials, allowing them to impersonate legitimate users.
- Data Theft: Malicious scripts could be used to extract sensitive data from the SolarWinds Observability platform and transmit it to an attacker-controlled server.
- Phishing Attacks: The injected script could be used to display fake login forms or other phishing content, tricking users into revealing their credentials.
- System Manipulation: In some cases, the injected script might be able to interact with the SolarWinds Observability platform’s API, potentially allowing the attacker to modify system configurations or perform other unauthorized actions.
- Defacement: The injected script could modify the visual appearance of the SolarWinds Observability interface.
Mitigation and Patch Steps
SolarWinds has released a patch to address CVE-2025-26391. It is highly recommended to apply the following steps:
- Upgrade to SolarWinds Observability Self-Hosted version 2025.4.1 or later. This version contains the necessary security fixes to remediate the XSS vulnerability.
- Review User Permissions: Ensure that users are assigned the minimum necessary privileges to perform their tasks.
- Implement a Web Application Firewall (WAF): A WAF can help to detect and block malicious requests, including those containing XSS payloads. While not a replacement for patching, it can provide an additional layer of security.
