CVE-2026-33102
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUrl redirection to untrusted site ('open redirect') in M365 Copilot allows an unauthorized attacker to elevate privileges over a network.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThis is an open redirect vulnerability in M365 Copilot where an attacker can craft malicious URLs that redirect users to untrusted external sites. The vulnerability allows unauthorized privilege escalation over a network, likely by tricking authenticated users into visiting attacker-controlled pages that steal session tokens or credentials.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Inspect Copilot-generated URLs for redirect parametersReview any URLs created by or shared through M365 Copilot. Look for query parameters that could control destination (such as 'redirect', 'url', 'dest', 'target', or similar) and examine their values to see if they point to external domains outside your organization.Affected if Any Copilot URL contains a redirect parameter pointing to an untrusted or external domain.
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Monitor network logs for Copilot redirect activityExamine proxy, firewall, or SIEM logs for outbound connections from Copilot sessions to unexpected external domains. Search for HTTP 30x responses or URL patterns where Copilot URLs direct users to non-Microsoft domains.Affected if Logs show Copilot-generated URLs redirecting users to external sites outside your organization's allowed domains.
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Check for user-reported or bookmarked Copilot URLsSurvey users or scan bookmark repositories for any saved Copilot URLs. Extract and analyze the full URL to identify if any contain external redirect destinations or unusual parameter structures.Affected if Saved or shared Copilot URLs contain redirect parameters leading to external websites.
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Review custom Copilot extensions or pluginsAudit any third-party extensions, plugins, or custom integrations connected to M365 Copilot. Check their configurations for any hardcoded or dynamic redirect endpoints that send users to external URLs.Affected if Custom extensions or plugins are configured to redirect Copilot traffic to external domains.
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Analyze authentication token exposure patternsReview security logs for instances where users may have visited attacker-controlled URLs through Copilot redirects. Look for signs of session token theft or unexpected authentication events involving Copilot domains.Affected if Authentication logs show session tokens or credentials were transmitted to suspicious domains via Copilot redirects.
Your environment is affected if any Copilot-generated URLs, logs, or extensions contain redirect parameters that send users to untrusted external domains, or if users report being redirected to unexpected sites through Copilot interactions.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply Microsoft security patches for M365 Copilot once available. Until then, users should avoid clicking untrusted links and organizations should monitor for suspicious redirect patterns in Copilot-generated URLs.
- Consultation4.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-33102 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-33102 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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