CVE-2025-6493
Description
A flaw was found in codemirror. The markdown.js file within the Markdown Mode component exhibits inefficient regular expression usage, leading to excessive resource consumption. This flaw allows a remote attacker to provide a specially crafted file. This inefficient processing can result in a denial of service.
Statement
This vulnerability is an inefficient regular expression complexity issue, also known as a Regular Expression Denial of Service (ReDoS), in the Markdown mode component. A remote, unauthenticated attacker can submit a specially crafted input that causes a denial of service (DoS) due to excessive CPU consumption. While the vulnerability is easily exploitable, it only impacts the availability of the component processing the markdown, and does not lead to a compromise of data or system integrity.
The assigned severity is Moderate because the flaw, while easy to exploit remotely without authentication, has its impact limited to a denial of service. It does not allow for unauthorized access to data or arbitrary code execution, which would warrant a higher rating.
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.
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 | 5.3 | 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 | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | Low | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Attackers can create crafted inputs that intentionally cause the regular expression to use excessive backtracking in a way that causes the CPU consumption to spike.
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