Publish a security.txt file

Why it matters

A security.txt file tells researchers who to contact when they find a security problem on your site, so a report reaches you instead of being posted publicly or lost. It is a small plain text file defined in RFC 9116.

The fix

1. Create a plain text file named security.txt with at least a Contact line and an Expires line. The snippet is a starting point; use a mailbox that exists and that somebody reads.
2. Publish it at https://example.com/.well-known/security.txt over https as text/plain; charset=utf-8. Serving it directly is simplest; a redirect is allowed.
3. The Expires date in the snippet is just under a year ahead, as RFC 9116 recommends. Put a reminder in your calendar to renew the file before it passes.
4. Open the address in a browser to confirm the file shows as plain text.

Contact: mailto:security@example.com
Expires: 2026-12-31T23:59:59Z
Preferred-Languages: en
Canonical: https://example.com/.well-known/security.txt

The examples use example.com. Replace it with your own domain.

Read the documentation ↗(opens in a new tab)

Related

• Reported by the security.txt check
• Serve security.txt from /.well-known/
• Serve security.txt over https
• Serve security.txt as text/plain with utf-8
• Add a Contact line to security.txt
• Fix the Contact value in security.txt
• Add an Expires line to security.txt
• Use an RFC 3339 date in the Expires line
• Renew the expired security.txt
• Renew security.txt before it expires
• Shorten the security.txt Expires date
• Fix repeated or insecure fields in security.txt
• Make the Canonical line match where the file is served