Add “Reauthentication After Risk Events” section and cross-links in Authentication, Session Management, and MFA cheat sheets

[pankajtaneja5]

Summary

This PR introduces a new Reauthentication After Risk Events section in the Authentication Cheat Sheet and adds cross-links to it from two related documents:

1. Session_Management_Cheat_Sheet.md

   • Under Session ID Life Cycle, adds a link pointing to the new reauthentication guidance.

2. Multifactor_Authentication_Cheat_Sheet.md

   • In the Adaptive or Risk-Based Authentication section, adds a link to the same reauthentication guidance.

3. Authentication_Cheat_Sheet.md

   • Adds the full Reauthentication After Risk Events section, detailing when and how to trigger reauthentication after high-risk activities (e.g., password resets, suspicious logins, account recovery).

Motivation

Developers often need to know when to require users to reauthenticate following critical security events. By:

• Centralizing best practices in the Authentication Cheat Sheet, and
• Surface-linking that section directly from session-management and MFA contexts,

we make it easy to discover and implement consistent reauthentication flows across applications.

Changes

• Authentication_Cheat_Sheet.md

  • Add new Reauthentication After Risk Events section with guidance on triggers, mechanisms, and implementation recommendations.

• Session_Management_Cheat_Sheet.md

  • Insert cross-link under Session ID Life Cycle to the new reauthentication section.

• Multifactor_Authentication_Cheat_Sheet.md

  • Insert cross-link in Adaptive or Risk-Based Authentication section to the same reauthentication section.

Next Steps

• Once merged, readers will be able to jump from session- and MFA-focused guidance straight to the detailed reauthentication best practices.
• Feedback welcome on link placement, section content, or further integrations!

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[kwwall]

Just ran into this and thought it would be worth mentioning here as a cautionary tale: https://tailscale.com/blog/frequent-reauth-security?lid=5wso20mx4knj

[szh]

Love this work, amazing job. LGTM!

[pankajtaneja5]

Thanks for the suggestion, @kwwall! I’ve added the Tailscale post under Additional Resources. Could you please take another look when you get a chance?

@szh can you please review again!

Also tagging @mackowski and @jmanico for review. Thanks!

[pankajtaneja5]

Hi @mackowski, thanks again for your review! I’ve removed the legacy V1 contributor entry and fixed the cross-sheet link—could you please take another look and re-approve when you have a moment?

Also, since @kwwall is on hiatus until the end of June, could someone with admin rights please dismiss the pending review request from @kwwall so we can merge as soon as we have two active approvals? Thanks everyone! 🙏