high7.5
CVE-2026-59887
linkify-it: Quadratic-complexity DoS via the `mailto:` validator scan-loop on attacker text
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | linkify-it | <= 5.0.1 | 5.0.2 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Markdown-It | Linkify-It | before 5.0.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-v245-v573-v5vm
- https://github.com/markdown-it/linkify-it/security/advisories/GHSA-v245-v573-v5vm
- https://nvd.nist.gov/vuln/detail/CVE-2026-59887
- https://github.com/markdown-it/linkify-it/commit/105e5d77f7d119871d2b2d86ed208568eb3e7ffe
- https://github.com/markdown-it/linkify-it/releases/tag/5.0.2