Auth bypass in Microsoft Ufo

CVE-2026-46544

Microsoft UFO open-source framework for intelligent automation across devices and platforms. In 3.0.1-4-ge2626659, Microsoft UFO accepts client-supplied session_id values in WebSocket task messages and reuses an existing in-memory session object if that session_id already exists. If a prior session has completed and remains in memory with populated results, a different authenticated client can send a new TASK message using the same session_id. The server re-enters the existing session object and sends the stale stored result to the new requester through the normal send_task_end() callback path. This is an authenticated cross-client stale result replay issue. The issue requires that the attacker knows or can predict a live or recently completed session_id.

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.004 (35.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-46544?
CVE-2026-46544 is a medium-severity vulnerability in Microsoft Ufo, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.3/10. Published 2026-05-27.
How severe is CVE-2026-46544?
Medium severity. CVSS v3 base score is 5.3 out of 10.