CVE-2026-63430
Description
A flaw was found in ammonia. This vulnerability allows a remote attacker to conduct cross-site scripting (XSS) by submitting specially crafted markup to an application configured to permit specific Mathematical Markup Language (MathML) tags and raw-text elements. Because ammonia does not correctly handle namespace parsing changes after removing tag attributes, the sanitized output is reinterpreted differently by the web browser. Consequently, an attacker can execute arbitrary JavaScript in the context of a user's browser session when the output is rendered.
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 | 4.7 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | High | 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 | Low | N/A | N/A |
| Integrity Impact | Low | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N
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