CVE-2026-6653
Description
A flaw was found in libxml2. A remote attacker can exploit a use-after-free vulnerability in the xmlParseInternalSubset function by providing maliciously crafted XML input. This improper handling of entity resolution can lead to a denial-of-service (DoS), making the affected system or application unavailable.
Statement
This Moderate impact use-after-free vulnerability in libxml2 can lead to a denial of service in Red Hat products that process untrusted XML input. In the worst-case scenario, a remote attacker is able to provide specially crafted XML, which, if parsed by an affected application, could cause the application to crash.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Updating to a fixed version of libxml2 (2.11.0 or later upstream, or a future RHEL errata) will fully resolve this issue.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | 9.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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