CVE-2026-48801 PUBLISHED

linkify-it: Quadratic algorithmic complexity in LinkifyIt#match scan loop

Assigner: GitHub_M
Reserved: 22.05.2026 Published: 14.07.2026 Updated: 15.07.2026

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.

Metrics

CVSS Vector: 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
CVSS Score: 8.7

Product Status

Vendor markdown-it
Product linkify-it
Versions
  • Version < 5.0.1 is affected

References

Problem Types

  • CWE-1333: Inefficient Regular Expression Complexity CWE