CVE-2016-3378

What it is

Open redirect vulnerability in Microsoft Exchange Server 2013 SP1, 2013 Cumulative Update 12, 2013 Cumulative Update 13, 2016 Cumulative Update 1, and 2016 Cumulative Update 2 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a crafted URL, aka "Microsoft Exchange Open Redirect Vulnerability."

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data tampering.

Exploit odds

15.3% chance of exploitation in the next 30 days (EPSS). Higher than most.

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2016-09-14 10:59 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 00:45 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 15.3% in the next 30 days (EPSS).
• Severity: 7.4 HIGH (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2016-09-14 10:59 UTC

Last modified

2026-06-17 00:45 UTC

Exploit probability

15.3% · EPSS, next 30 days

Weakness

CWE-20 · Improper input validation

Record status

Modified

Affected

• Microsoft Exchange Server 2013
• Microsoft Exchange Server 2016

Attack profile CVSS 3.0 · 7.4

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Changed

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2016-3378.md and follow it. Check whether this project is affected by CVE-2016-3378. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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