CVE Tools
Track your stack

CVE-2021-31955

Exploited in the wild. In CISA KEV since 2021‑11‑03. Fixed versions are out.

CVSS 3.15.5MediumEPSS percentile99th81% chance in 30 daysCISA KEVListedsince 2021-11-03, due 2021-11-17
No public exploit knownFix3 products5 fixed builds listed below

Published Updated Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • Microsoft Windows 10 Version 1809Affected: ≥ 10.0.0, < 10.0.17763.1999Upgrade to: 10.0.17763.1999Affected: ≥ 10.0.0, < 10.0.18363.1621Upgrade to: 10.0.18363.1621Affected: ≥ 10.0.0, < 10.0.19043.1052Upgrade to: 10.0.19043.1052Affected: ≥ 10.0.0, < 10.0.19041.1052Upgrade to: 10.0.19041.1052 + 1 more branchStated by: CVE record
  • Microsoft Windows Server 2019Affected: ≥ 10.0.0, < 10.0.17763.1999Upgrade to: 10.0.17763.1999Stated by: CVE record
  • Microsoft Windows Server version 2004Affected: ≥ 10.0.0, < 10.0.19041.1052Upgrade to: 10.0.19041.1052Affected: ≥ 10.0.0, < 10.0.19042.1052Upgrade to: 10.0.19042.1052Stated by: CVE record

Versions as the sources state them. Full version matrix after sign-in

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

Coverage timeline

0 publishers

  1. Added to CISA KEV catalog

    ·CISA KEV

Sourced from public security reporting — each date is when it was published, not when it happened.

What it is

From the CVE record

Windows Kernel Information Disclosure Vulnerability

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS99th
CISA KEV
CISA KEV

Listed as exploited in the wild since 2021-11-03.

US federal agencies must remediate by 2021-11-17.

Apply updates per vendor instructions.
Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

81% chance of exploitation activity in the next 30 days, which ranks it in the 99th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

7 events over 1843 days, from the signal feeds we watch.

  1. OpenVAS check added
  2. EPSS band changelow → high
  3. Patch availablerecord updated
  4. Added to CISA KEV
  5. Publishedweakness classified

Affected products

And 23 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Scored 5.5 by NVD.

How it is reached

  • Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required LowRequires basic user-level privileges
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity NoneNo integrity impact
  • Availability NoneNo availability impact

Weaknesses

Sources

References in the record

And 2 more references. See all after sign-in

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next exploited one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for Windows 10 Version 1809, not every advisory. This one: actively exploited.