CVE-2026-48801: linkify-it is a links recognition library with full Unicode support

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HIGH 7.5REMOTEUPGRADE

CVE-2026-48801 is a high-severity flaw (CVSS 7.5) affecting linkify-it. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 68%)
CISA exploited list	No
Weakness	CWE-1333
Published	2026-07-14
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: markdown-it

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-14 21:17 UTCPublished CVE record published
2026-10-24 21:10 UTCUpdated Record last modified

markdown-it linkify-it UPGRADE

Affected: < 5.0.1

Fixed in: 5.0.1

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls linkify-it

2. UPGRADE to 5.0.1

npm install linkify-it@">=5.0.1"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-48801?

linkify-it: upgrade to 5.0.1. Exact commands for each OS are on this page.

Is CVE-2026-48801 being exploited?

CVE-2026-48801 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48801 affect?

CVE-2026-48801 affects linkify-it. Severity is high (CVSS 7.5). 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

How urgent is CVE-2026-48801?

Priority 44/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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