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TI-2026-81017 Aliases CVE-2026-117470GHSA-3gq2-hx4p-69qc

WebAuthn assertion replay permits second-factor bypass in Psono Server

Priority LOW 29CWE-294Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Security bypass
Confidentiality · integrity · availability
Low · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-294.

Summary

Psono Server CE and EE versions from 3.1.0 before 7.2.4 do not consume a stored WebAuthn challenge after assertion verification, which is CWE-294 (authentication bypass by capture-replay). An unauthenticated remote attacker who possesses the user's password and has captured one valid WebAuthn assertion can replay that assertion with separate login tokens while the stored challenge stays unchanged, bypassing the WebAuthn second factor. The attack requires capture of a valid assertion and does not by itself disclose plaintext secrets.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00408 35th percentileScored 2026-11-07
Fix Fixed Psono (esaqa GmbH): 7.2.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
esaqa GmbHPsono3.1.0 to before 7.2.47.2.4Patch availableCNA
  • Psono Vendoresaqa GmbH Affected 3.1.0 to before 7.2.4 Fixed in 7.2.4 Patch available CNA

Remediation

Upgrade esaqa GmbH Psono to version 7.2.4 or later, which fixes the issue. The sources list no vendor advisory identifier for this fix.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

  • Fix · CNA Psono (esaqa GmbH) Fixed in 7.2.4

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    esaqa Psono 7.2.4

    5 records Highest priority Priority LOW 5 LOW

    Other records, highest priority first

    • TI-2026-81015 Device-code claim permits restricted token escalation in Psono ServerPriority LOW 29
    • TI-2026-81018 User-controlled Duo host enables SSRF in Psono ServerPriority LOW 24
    • TI-2026-81016 Psono file-transfer confusion allows unauthorized repository writesPriority LOW 24
    Show all 5 records →

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-117470
  2. 2026-10-27 Alias added: GHSA-3gq2-hx4p-69qc
  3. 2026-10-27 Priority changed: MEDIUM → LOW
  4. 2026-11-04 CISA SSVC decision points changed

References

Patch 1

Advisory 1

Other 3

  • TI-2025-01732 Stored XSS in Psono-Client via Malicious Vault Entry URLs CVSS 4.0CRITICAL 9.3
  • TI-2026-81015 Device-code claim permits restricted token escalation in Psono Server CVSS 3.1MEDIUM 6.5
  • TI-2026-81018 User-controlled Duo host enables SSRF in Psono Server CVSS 3.1MEDIUM 5.4
  • TI-2026-81016 Psono file-transfer confusion allows unauthorized repository writes CVSS 3.1MEDIUM 5.4
  • TI-2026-81021 URL prefix handling permits API key read-scope bypass in Psono Server CVSS 3.1MEDIUM 4.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences