How severe is CVE-2026-85887?

CVE-2026-85887 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-85887 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-85887?

CVE-2026-85887 affects Microsoft 365 Copilot. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-85887?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-85887 published?

CVE-2026-85887 was published on 2026-09-18 and last updated on 2026-09-28.

CVE-2026-85887

CVE-2026-85887 is a high-severity vulnerability in Microsoft 365 Copilot with a CVSS 3.x base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-732.

Key facts

Severity: High (CVSS 3.x base score 7.7)
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-732
Affected product: Microsoft 365 Copilot
Published: 2026-09-18
Last modified: 2026-09-28

Description

Incorrect permission assignment for critical resource in M365 Copilot allows an authorized attacker to disclose information over a network.

Frequently asked questions

What is CVE-2026-85887?: Incorrect permission assignment for critical resource in M365 Copilot allows an authorized attacker to disclose information over a network.
How severe is CVE-2026-85887?: CVE-2026-85887 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-85887 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-85887?: CVE-2026-85887 affects Microsoft 365 Copilot. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-85887?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-85887 published?: CVE-2026-85887 was published on 2026-09-18 and last updated on 2026-09-28.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85887

Affected products (1)

cpe:2.3:a:microsoft:365_copilot:-:*:*:*:*:*:*:*

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