The Radar post-quantum TLS support checker now also reports TLS bugs detected during the handshake test. When a scanned host exhibits compatibility issues, the results include details on the specific bugs detected, along with guidance on how to investigate and remediate each issue. The bugs section only appears for hosts where issues are found.
The following TLS bugs are detected:
- Split ClientHello — The connection fails with a fragmented post-quantum
ClientHellobut succeeds with classical handshakes. Typically caused by middleboxes or firewalls that cannot reassemble split TLS messages. - HRR Failure — The server sends a
HelloRetryRequestbut fails to complete the handshake afterward. - Unknown Keyshare — The server cannot handle unknown key exchange algorithms and fails instead of responding with a
HelloRetryRequestas required by the TLS 1.3 specification.
Bug detection data is available through the existing /post_quantum/tls/support endpoint.
Visit the Post-Quantum Encryption page to test a host.
Source: Cloudflare
Latest Posts
- Microsoft SharePoint Online: Retirement of Restricted SharePoint Search [MC1395311]
![Microsoft SharePoint Online: Retirement of Restricted SharePoint Search [MC1395311] 2 pexels mhmd sedky 1725307 3286817](data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==)
- AWS Secrets Manager introduces safe secrets handling in the Agent Toolkit for AWS

- Microsoft Entra: New service plans for Conditional Access and ID Protection for agents [MC1395007]
![Microsoft Entra: New service plans for Conditional Access and ID Protection for agents [MC1395007] 4 pexels olly 3764392](data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==)
- (Updated) Outlook Mobile: Follow a meeting option [MC1248393]
![(Updated) Outlook Mobile: Follow a meeting option [MC1248393] 5 pexels pixabay 209728](data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==)

![Microsoft SharePoint Online: Retirement of Restricted SharePoint Search [MC1395311] 2 pexels mhmd sedky 1725307 3286817](https://mwpro.co.uk/wp-content/uploads/2025/06/pexels-mhmd-sedky-1725307-3286817-150x150.webp)

![Microsoft Entra: New service plans for Conditional Access and ID Protection for agents [MC1395007] 4 pexels olly 3764392](https://mwpro.co.uk/wp-content/uploads/2024/08/pexels-olly-3764392-150x150.webp)
![(Updated) Outlook Mobile: Follow a meeting option [MC1248393] 5 pexels pixabay 209728](https://mwpro.co.uk/wp-content/uploads/2024/08/pexels-pixabay-209728-150x150.webp)
