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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.

PUBLISHED Reserved 2026-05-22 | Published 2026-07-14 | Updated 2026-07-14 | Assigner GitHub_M




HIGH: 8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Problem types

CWE-1333: Inefficient Regular Expression Complexity

Product status

< 5.0.1
affected

References

github.com/...ify-it/security/advisories/GHSA-22p9-wv53-3rq4

github.com/...ommit/6be6d15e0641bf1daeaa977d500cabc743166159

cve.org (CVE-2026-48801)

nvd.nist.gov (CVE-2026-48801)

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