CVE-2026-20805Microsoft Windows Information Disclosure Vulnerability
CVE-2026-20805 is a information exposure in Microsoft Windows, rated medium (5.5 on CVSS 3.1).
Why this priority: Exploited in the wild: listed in CISA's KEV catalog.
Published · Updated · NVD status: Analyzed
What it is
The software reveals data to someone who should not see 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, and nobody has to click anything.
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?
CISA added it to the Known Exploited Vulnerabilities catalog on 2026-01-13: it is being exploited in the wild. EPSS estimates a 7.5% chance of exploitation activity in the next 30 days, higher than 95% of scored CVEs.
What to do
- Treat it as urgent: it is on CISA's KEV list. CISA's deadline for US federal agencies: 2026-02-03.
- Apply the update for your edition of Microsoft Windows. Fixed builds: Windows 10 Version 1607: 10.0.14393.8783; Windows 10 Version 1809: 10.0.17763.8276; Windows 10 Version 21H2: 10.0.19044.6809; Windows 10 Version 22H2: 10.0.19045.6809; Windows 11 Version 23H2: 10.0.22631.6491; Windows 11 Version 24H2: 10.0.26100.7623; and 13 more on this page.
- Limit who can run code or sign in on the hosts that run it.
- Check exposed instances for signs of compromise, not only for the version.
Description from NVD
Exposure of sensitive information to an unauthorized actor in Desktop Windows Manager 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
- Operating systems on servers, workstations or devices. Everything on the host inherits the flaw.
- 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
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- 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 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.