CVE-2026-59887 | linkify-it is a links recognition library with full Unicode … | CVSS 7.5 HIGH

Description

linkify-it is a links recognition library with full Unicode support. Prior to 5.0.2, the mailto: schema validator used by .test() and .match() can be invoked at every mailto: occurrence and scan the remaining input through src_email_name in lib/re.mjs, causing O(n^2) CPU consumption on crafted user text. This issue is fixed in version 5.0.2.

Metadata

CVE ID: CVE-2026-59887
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-07-07 16:40 UTC
Published: 2026-07-08 15:58 UTC
Last updated: 2026-07-09 14:41 UTC
Primary CWE: CWE-407
CWE-407: Inefficient Algorithmic Complexity
Vendor / Product: markdown-it / linkify-it
Sources: cve.org · NVD

Severity & Metrics

7.5 HIGH CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: yes
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
markdown-it	linkify-it	—	< 5.0.2

Weakness (CWE)

CWE	Source	Description
CWE-407	cna	CWE-407: Inefficient Algorithmic Complexity

CVSS scores (1)

Score	Severity	Version	Source	Vector
7.5	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References (3)

https://github.com/markdown-it/linkify-it/security/advisories/GHSA-v245-v573-v5vm https://github.com/markdown-it/linkify-it/security/advisories/GHSA-v245-v573-v5vm
https://github.com/markdown-it/linkify-it/commit/105e5d77f7d119871d2b2d86ed208568eb3e7ffe https://github.com/markdown-it/linkify-it/commit/105e5d77f7d119871d2b2d86ed208568eb3e7ffe
https://github.com/markdown-it/linkify-it/releases/tag/5.0.2 https://github.com/markdown-it/linkify-it/releases/tag/5.0.2