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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.007 (51.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003
Affected products
- Microsoft Ufo — versions 3.0.1-4-ge2626659
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.