CVE-2026-105557Microsoft Windows Server 2016 system information exposure
CVE-2026-105557 is a system information exposure in Microsoft Windows Server 2016, rated medium (5.9 on CVSS 3.1).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Awaiting Analysis
What it is
Internal system details are exposed to outsiders.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything. Success also depends on conditions the attacker does not fully control.
What an attacker gains
A successful attack can read the data it protects. In practice, this kind of flaw lets an attacker learn data or internals that help a follow-up attack.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Apply the update for your edition of Microsoft Windows Server 2016. Fixed builds: Windows Server 2016: 10.0.14393.9688; Windows Server 2016 (Server Core installation): 10.0.14393.9688. Other affected products have their own fixed versions on this page.
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
Exposure of sensitive system information to an unauthorized control sphere in Windows DHCP Server allows an unauthorized attacker to disclose information over a network.
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
- Error responses, logs and debug endpoints. The flaw sits between internal data and whoever can read the response or log.
- APIs that over-share. The flaw sits between internal data and whoever can read the response or log.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- Between internal data and whoever can read the response or log. An attacker who crosses it can learn data or internals that help a follow-up attack.
Questions to answer about your own systems
- Where does Microsoft Windows Server 2016 run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- 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.