9.8

CVE-2026-54130: microsoft 365_copilot

CVSS: 9.8v3.1CriticalAnalyzed
Published 18-06-2026Last modified 24-09-2026
Open JSON

Vulnerability summary

CVE-2026-54130 is a critical (CVSS 9.8) vulnerability in microsoft 365_copilot. EPSS estimates a 1.08% chance of exploitation in the next 30 days, higher than 64.7% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
1.08%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 18-06-2026
    PublishedVulnerability first disclosed.
  2. 24-09-2026
    Last modifiedVulnerability information updated.

Description

Missing authentication for critical function in M365 Copilot allows an unauthorized attacker to disclose information over a network.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

1.08%

Chance of exploitation in the next 30 days

Percentile

65%

Versus all other CVEs

30-day change

0.00 pp

From 1.08% on 20-09-2026

20-09-202620-10-2026
EPSS score
1.08%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Microsoft2 products

1 vendor · 2 products

References

1 links