CVE-2026-33102 | Microsoft 365 Copilot Elevation of Privilege Vulnerability

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

Published: 2026-04-23 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-33102 is rated Moderate Risk (43.2/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.05%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-33102

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-25 0.04% 0.05% +0.01%
2 2026-04-24 0.04%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33102

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.3 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 5.8 [email protected]

Weakness enumeration for CVE-2026-33102

GitHub Security Advisory for CVE-2026-33102

GHSA-q6x5-8v4h-crwr · Severity: critical — Url redirection to untrusted site ('open redirect') in M365 Copilot allows an unauthorized...

Affected software / configurations for CVE-2026-33102

Vendor Product Version Raw CPE
microsoft 365_copilot cpe:2.3:a:microsoft:365_copilot:-:*:*:*:*:*:*:*

References for CVE-2026-33102

cvelogic Threat Intelligence