CVE-2026-118694
Description
A flaw was found in markdown2. A remote attacker can cause a Denial of Service (DoS) by submitting specially crafted Markdown content containing repeated unclosed inline link sequences. Processing these malformed links causes the parser to repeatedly rescan the text, exhausting CPU resources and making the service unresponsive.
Statement
This vulnerability is rated as an Important severity flaw because an unauthenticated remote attacker can trigger complete CPU exhaustion without requiring elevated privileges or user interaction, rendering dependent services unavailable. Applications using markdown2 to render user-supplied content over the network are directly exposed to this denial-of-service condition. Services that process Markdown exclusively from trusted internal sources or isolated environments operate with reduced exposure.
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 | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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