Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:NSummary
CVE-2026-33102 is a critical-severity Open Redirect (CWE-601) vulnerability in Microsoft 365 Copilot. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Phishing (T1566); ranked at the 33th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as Enterprise AI Assistants; in the Other ATLAS/OWASP Terms risk domain.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-33102 is an open redirect vulnerability (CWE-601) affecting M365 Copilot, a component of Microsoft 365. The flaw enables URL redirection to untrusted sites, which can be exploited by unauthorized attackers over a network to elevate privileges. It has a CVSS v3.1 base score of 9.3 (AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N), indicating critical severity due to high confidentiality and integrity impacts with a change in scope.
An unauthorized attacker with network access can exploit this vulnerability by tricking a user into interacting with a malicious link or redirect (UI:R required). No prior privileges are needed (PR:N), and the attack has low complexity (AC:L). Successful exploitation allows privilege elevation, potentially leading to high-impact unauthorized access to sensitive data or actions within the M365 environment.
Microsoft's Security Response Center (MSRC) provides mitigation guidance and patch details in its update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33102. Security practitioners should consult this advisory for deployment instructions and verify system updates.
This vulnerability occurs in M365 Copilot, an AI-powered productivity tool, highlighting risks in AI-integrated enterprise software where open redirects could amplify phishing or social engineering attacks. No public evidence of real-world exploitation is available as of publication on 2026-04-23.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-25310
Vulnerability Data
Url redirection to untrusted site ('open redirect') in M365 Copilot allows an unauthorized attacker to elevate privileges over a network.
- CWE(s)
AI Security AnalysisAI
- AI Category
- Enterprise AI Assistants
- Risk Domain
- Other ATLAS/OWASP Terms
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: m365 copilot
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V3.7.2
Mitigating Controls (NIST 800-53 r5) AI
Input validation directly checks and rejects untrusted redirect targets before they are used in a response.
Information flow enforcement can restrict redirects to only approved/trusted destinations, stopping untrusted user-supplied URLs from being followed.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input validation and untrusted-redirect controls that prevent CWE-601.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Preventing access to attacker-controlled or malicious sites stops users from being redirected to untrusted locations via open-redirect or phishing links.