CVE-2026-48801 | linkify-it is a links recognition library with full Unicode … | CVSS 8.7 HIGH

Description

linkify-it is a links recognition library with full Unicode support. Prior to 5.0.1, LinkifyIt.prototype.match, the package's primary public API, has O(N²) algorithmic complexity for inputs containing many fuzzy links or emails because the JavaScript-level scan loop re-slices input and re-runs unanchored regex searches on progressively shorter tails. Any service that synchronously renders untrusted Markdown with linkify:true on a request hot path can inherit a worker-process denial of service triggerable by a tens-of-KB request body. This issue is fixed in version 5.0.1.

Metadata

CVE ID: CVE-2026-48801
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-05-22 20:18 UTC
Published: 2026-07-14 20:03 UTC
Last updated: 2026-07-14 20:03 UTC
Primary CWE: CWE-1333
CWE-1333: Inefficient Regular Expression Complexity
Vendor / Product: markdown-it / linkify-it
Sources: cve.org · NVD

Severity & Metrics

8.7 HIGH CVSS 4.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Affected products (1)

Vendor	Product	Platform	Versions
markdown-it	linkify-it	—	< 5.0.1

Weakness (CWE)

CWE	Source	Description
CWE-1333	cna	CWE-1333: Inefficient Regular Expression Complexity

CVSS scores (1)

Score	Severity	Version	Source	Vector
8.7	HIGH	4.0	cna	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References (2)

https://github.com/markdown-it/linkify-it/security/advisories/GHSA-22p9-wv53-3rq4 https://github.com/markdown-it/linkify-it/security/advisories/GHSA-22p9-wv53-3rq4
https://github.com/markdown-it/linkify-it/commit/6be6d15e0641bf1daeaa977d500cabc743166159 https://github.com/markdown-it/linkify-it/commit/6be6d15e0641bf1daeaa977d500cabc743166159