Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Markdown-It | Linkify-It | < 5.0.1 |
Related Weaknesses (CWE)
References
- https://github.com/markdown-it/linkify-it/commit/6be6d15e0641bf1daeaa977d500cabcPatch
- https://github.com/markdown-it/linkify-it/security/advisories/GHSA-22p9-wv53-3rqExploitVendor Advisory
- https://github.com/markdown-it/linkify-it/security/advisories/GHSA-22p9-wv53-3rqExploitVendor Advisory
FAQ
What is CVE-2026-48801?
CVE-2026-48801 is a vulnerability with a CVSS score of 7.5 (HIGH). 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...
How severe is CVE-2026-48801?
CVE-2026-48801 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-48801?
Check the references section above for vendor advisories and patch information. Affected products include: Markdown-It Linkify-It.