CVE-2026-123395Microsoft 365 Apps for Enterprise code injection
CVE-2026-123395 is a code injection in Microsoft 365 Apps for Enterprise, rated medium (5.9 on CVSS 3.1).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Undergoing Analysis
What it is
Input is evaluated as code by the application, so an attacker's code runs inside it.
How it is reached
An attacker can exploit it by someone who can already run code or sign in on the machine, with an ordinary user account, but someone has to act first, such as opening a file or following a link.
What an attacker gains
A successful attack can read the data it protects. In practice, this kind of flaw lets an attacker run commands or code with the privileges of the affected service. The damage can spread past the vulnerable component into others.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- No fixed version is listed for Microsoft 365 Apps for Enterprise itself; fixed versions for the other affected products are listed on this page.
- Limit who can run code or sign in on the hosts that run it.
- Warn the people who use it, and filter files and links on the way in.
Description from NVD
Improper control of generation of code ('code injection') in Microsoft Office Excel allows an authorized attacker to disclose information locally.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Application servers and the hosts they run on. The flaw sits between untrusted input and code or command execution.
- Template engines. The flaw sits between untrusted input and code or command execution.
Trust boundaries in play
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- People who open files and links. Mail, chat and browsers are the delivery path.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
- Between untrusted input and code or command execution. An attacker who crosses it can run commands or code with the privileges of the affected service.
Questions to answer about your own systems
- Where does Microsoft 365 Apps for Enterprise run in your systems, and at which version?
- Which of those hosts also run code or users you do not fully trust?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.