What is CVE-2026-33102?

CVE-2026-33102 is a critical-severity vulnerability in Microsoft 365_copilot, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 9.3/10. Published 2026-04-23.

How severe is CVE-2026-33102?

Critical severity. CVSS v3 base score is 9.3 out of 10.

Open Redirect in Microsoft 365_copilot

CVE-2026-33102

Url redirection to untrusted site ('open redirect') in M365 Copilot allows an unauthorized attacker to elevate privileges over a network.

Vulnerability class: Open Redirect

EPSS: 0.001 (17.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N.

Affected products

Microsoft 365_copilot
Microsoft 365 Copilot

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

Microsoft 365 Copilot Elevation of Privilege Vulnerability (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-33102?: CVE-2026-33102 is a critical-severity vulnerability in Microsoft 365_copilot, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 9.3/10. Published 2026-04-23.
How severe is CVE-2026-33102?: Critical severity. CVSS v3 base score is 9.3 out of 10.