CVE-2026-55440

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7%, top 52% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Microsoft UFO open-source framework for intelligent automation across devices and platforms. Prior to 3.0.7, the COMMAND_RESULTS handler in ufo/server/ws/handler.py called get_or_create_session in ufo/server/services/session_manager.py without owner_client_id, allowing an authenticated client to create an unowned attacker-chosen session_id such as constellation_task_id = f"{task_name}@{task_id}" and deny the legitimate owner or exhaust memory with phantom sessions. This issue is fixed in version 3.0.7.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
48%
KEV
Not listed

Published

July 16, 2026

Last Modified

July 16, 2026

Advisory Details (3)

Auto-updated Jul 16, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

3.0.7

Patch available: microsoft/UFO 3.0.7

https://github.com/microsoft/UFO/releases/tag/3.0.7
github_commit Patch Available

commit cc653bde7533 (microsoft/UFO)

Patch available: microsoft/UFO 3.0.7 (contains commit cc653bde7533)

https://github.com/microsoft/UFO/commit/cc653bde75337ab60c320e6b7cb61b86ba6ca948
github Patch Available🟡 PoC Available

COMMAND_RESULTS handler creates unowned sessions, allowing authenticated session-squatting denial of service · Advisory · microsoft/UFO · GitHub

https://github.com/microsoft/UFO/security/advisories/GHSA-hxjv-fmjf-wmjf

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 16× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-27 09:34 UTCEG score recompute
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 11:25 UTCEG score recompute
  4. 2026-07-25 14:18 UTCEPSS rescore
  5. 2026-07-24 14:18 UTCEPSS rescore
  6. 2026-07-23 14:18 UTCEPSS rescore
  7. 2026-07-23 03:20 UTCEG score recompute
  8. 2026-07-22 14:08 UTCEPSS rescore
  9. 2026-07-21 15:25 UTCEPSS rescore
  10. 2026-07-20 17:08 UTCEPSS rescore
  11. 2026-07-19 14:31 UTCEPSS rescore
  12. 2026-07-19 14:31 UTCEPSS rescore
  13. 2026-07-19 02:29 UTCEPSS rescore
  14. 2026-07-18 10:04 UTCEPSS rescore
  15. 2026-07-16 15:54 UTCEG score recompute
  16. 2026-07-16 15:53 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55440?
CVE-2026-55440 is a medium vulnerability published on July 16, 2026. Microsoft UFO open-source framework for intelligent automation across devices and platforms. Prior to 3.0.7, the COMMANDRESULTS handler in ufo/server/ws/handler.py called getorcreatesession in ufo/server/services/sessionmanager.py without ownerclientid, allowing an authenticated client to create an…
When was CVE-2026-55440 disclosed?
CVE-2026-55440 was first published in the National Vulnerability Database on July 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55440 actively exploited?
CVE-2026-55440 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 52.1% of all scored CVEs.
What is the CVSS score of CVE-2026-55440?
CVE-2026-55440 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-55440?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55440, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-55440

Explore →

Is Your Infrastructure Affected by CVE-2026-55440?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs