CVE-2026-48801
Description
A flaw was found in linkify-it, a library for recognizing links with full Unicode support. The LinkifyIt.prototype.match function, the package's primary public API, has an algorithmic complexity of O(N²) for inputs containing many fuzzy links or emails. This can be exploited by a remote attacker sending a specially crafted request body, leading to a worker-process denial of service (DoS) due to excessive CPU usage when synchronously rendering untrusted Markdown with linkify enabled.
Statement
This Moderate impact flaw in linkify-it, a link recognition library, can lead to a denial of service in Red Hat products. The vulnerability arises from an O(N²) algorithmic complexity when processing untrusted Markdown with numerous fuzzy links or emails, potentially causing excessive CPU consumption and worker-process unavailability. This risk is present in services that synchronously render untrusted Markdown with the linkify feature enabled.
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 | 7.5 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/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:N/I:N/A:H
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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