CVE-2026-15928
Description
A flaw was found in the XMLRPC-C Library. This reflected cross-site scripting (XSS) vulnerability exists in the error page component. A remote attacker could exploit this by tricking a user into clicking a specially crafted link. Successful exploitation could lead to the execution of malicious scripts in the user's browser, potentially resulting in information disclosure or session hijacking.
Statement
This reflected cross-site scripting (XSS) vulnerability relies entirely on client-side interaction through a web browser. Practical exploitation requires a remote attacker to trick a user into clicking a targeted link that passes crafted input to an application displaying the XMLRPC-C error page. If executed, the script runs within the context of the user's browser session, making sensitive session tokens or client-side data accessible to the attacker.
While external CVSSv4 scoring rates this flaw to an 8.2 High, Red Hat bounds the severity to CVSS 7.4 based on explicit CIA triad mechanics. The impact is strictly confined to Confidentiality (C:H) via potential browser-side data disclosure. The flaw carries zero impact on system Integrity (I:N) or Availability (A:N), as it cannot alter server-side application logic, modify stored data, or disrupt underlying XML-RPC services.
Deployments operating strictly as headless backend services, non-interactive daemons, or server-to-server API endpoints—where the XMLRPC-C error component is never exposed or rendered inside a user's web browser—are fundamentally outside the execution boundary of this flaw and remain at zero risk.
Mitigation
To mitigate this issue, ensure that applications utilizing the XMLRPC-C library do not directly expose its error pages to end-users via a web browser. Configure web servers or application frontends to intercept and sanitize or replace error responses originating from XMLRPC-C before they are rendered client-side. Alternatively, restrict XMLRPC-C deployments to backend services that do not present error output in a user-facing web interface.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.4 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | Required | N/A | N/A |
| Scope | Changed | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
Understanding the Weakness (CWE)
Access Control,Confidentiality
Technical Impact: Bypass Protection Mechanism; Read Application Data
The most common attack performed with cross-site scripting involves the disclosure of private information stored in user cookies, such as session information. Typically, a malicious user will craft a client-side script, which -- when parsed by a web browser -- performs some activity on behalf of the victim to an attacker-controlled system (such as sending all site cookies to a given E-mail address). This could be especially dangerous to the site if the victim has administrator privileges to manage that site. This script will be loaded and run by each user visiting the web site. Since the site requesting to run the script has access to the cookies in question, the malicious script does also.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
In some circumstances it may be possible to run arbitrary code on a victim's computer when cross-site scripting is combined with other flaws, for example, "drive-by hacking."
Confidentiality,Integrity,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Read Application Data
The consequence of an XSS attack is the same regardless of whether it is stored or reflected. The difference is in how the payload arrives at the server. XSS can cause a variety of problems for the end user that range in severity from an annoyance to complete account compromise. Some cross-site scripting vulnerabilities can be exploited to manipulate or steal cookies, create requests that can be mistaken for those of a valid user, compromise confidential information, or execute malicious code on the end user systems for a variety of nefarious purposes. Other damaging attacks include the disclosure of end user files, installation of Trojan horse programs, redirecting the user to some other page or site, running "Active X" controls (under Microsoft Internet Explorer) from sites that a user perceives as trustworthy, and modifying presentation of content.
Frequently Asked Questions
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