SB2026083169 - Inefficient regular expression complexity in linkify-it

Description

This security bulletin contains information about 1 vulnerability.

1) Inefficient regular expression complexity (CVE-ID: CVE-2026-48801)

CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity

CVSSv4: 8.7 [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]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to inefficient regular expression complexity in LinkifyIt.prototype.match when processing user-supplied text containing many fuzzy links or email-like strings. A remote attacker can send a specially crafted request body to cause a denial of service.

This affects services that synchronously render untrusted Markdown with linkification enabled on the request path, including transitive use through markdown-it with linkify:true.

Remediation

Install update from vendor's website.

References

• https://github.com/advisories/GHSA-22p9-wv53-3rq4
• https://github.com/markdown-it/linkify-it/security/advisories/GHSA-22p9-wv53-3rq4