Published: October 27, 2026 | Last Modified: October 27, 2026
Psono Server CE & EE versions 3.1.0 through 7.2.3 did not consume a stored WebAuthn challenge after assertion verification. An unauthenticated remote attacker who possessed the user's password and one captured valid WebAuthn assertion could replay that assertion with separate login tokens while the stored challenge remained unchanged, bypassing the WebAuthn second factor. The attack required capture of a valid assertion and did not itself disclose plaintext secrets.
This analysis is generated by Ghostwire from NVD, CISA KEV, EPSS, and open-source intelligence data. Verify findings through primary sources before acting.