CVE-2026-102342
Description
A flaw was found in ammonia. This flaw allows stored Cross-Site Scripting (XSS) in applications configured to permit SVG animate or set elements. The sanitizer fails to properly neutralize animation attributes that target link destinations with JavaScript URIs. A remote attacker can exploit this vulnerability by supplying crafted SVG content, creating clickable links that execute arbitrary script in the user's browser session.
Statement
A MODERATE severity stored cross-site scripting (XSS) flaw was found in ammonia, a Rust HTML sanitization library that is shipped in Red Hat Enterprise Linux (via the rust and rust-toolset components) and bundled in other Red Hat products such as Red Hat Ansible Automation Platform, Red Hat Satellite, and Red Hat In-Vehicle OS through the ammonia crate or its nh3 Python bindings. When an application using ammonia is configured to permit the SVG animate or set elements, the sanitizer fails to neutralize animations that set a link's href attribute to a javascript: URI. A remote attacker who can store crafted SVG content in such an application can create a clickable link that executes attacker-controlled script in the application's origin when a victim clicks it, allowing actions to be performed on behalf of the victim and access to their session data. The Red Hat CVSS 3.1 score of 5.4 (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N) matches the upstream severity. Ansible Automation Platform components whose bundled ammonia version is outside the affected range are not affected because the vulnerable code is not present. For in-support Red Hat products the fix is currently deferred: the flaw is rated MODERATE with a CVSS score below 7.0, which does not meet Red Hat's threshold for filing fix trackers at this severity, and the residual risk is limited to applications that explicitly allow the SVG animate or set tags, with exploitation further requiring a victim to click the crafted link. The affected Fedora and EPEL python-nh3 packages are delegated to the community, where a fix is being pursued; streams that are out of support scope will not receive a fix through Red Hat update channels.
Mitigation
A workaround exists for applications that use ammonia: remove the SVG animate and set elements from the sanitizer's allowed-tags configuration. Applications that do not permit these tags are not affected by this flaw. Otherwise, upgrade to an upstream release containing the fix (ammonia 3.3.3, 4.0.3, or 4.1.4, depending on the major version in use); for Red Hat products, apply updates when they become available through the appropriate support channels.
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 | 5.4 | N/A | 5.4 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | Required | N/A | Required |
| Scope | Changed | N/A | Changed |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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.
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