CVE-2026-59887
linkify-it: Quadratic-complexity DoS via the `mailto:` validator scan-loop on attacker text
HIGH 7.5EPSS 0.6%
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.
- Affected
- markdown-it · linkify-it
- CVSS v3.1 GITHUB
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.64% chance of exploitation in the next 30 days, 50th percentile
- Published
- 2026-07-08
- Updated
- 2026-07-09
Proof-of-concept exploits (1)
Security advisories
- markdown-it/linkify-it/security/advisories/GHSA-v245-v573-v5vm
- markdown-it/linkify-it/commit/105e5d77f7d119871d2b2d86ed208568eb3e7ffe