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CVE-2026-96951

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Microsoft Windows. For every flaw being used in attacks, see Exploited flaws; for Microsoft’s, see Microsoft flaws being used in attacks.

CVE-2026-96951 is a security flaw in Microsoft Windows, Microsoft’s operating system for PCs and servers. Attackers can run commands on Microsoft Windows. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 13 Oct 2026.[1]

Microsoft Windows is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Fixed in version 154.0.4258.62, 20260925.100, 10.0.14393.9612 and 10.0.17763.9376 and others.

Description

CISA calls it a command injection in Microsoft Windows. In its words: “Microsoft Windows Shell contains a command injection vulnerability that allows an unauthorized attacker to bypass a security feature over a network.”[1]

The underlying weakness is command injection (CWE-77), in MITRE’s list of common software weaknesses.[2]

It scores 8.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by the organisation that published the CVE using CVSS 3.1.[2]

Affected versions

NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]

ProductFixed in
Microsoft Edge (Chromium-based)154.0.4258.62
Outlook.com20260925.100
Windows 10 Version 160710.0.14393.9612
Windows 10 Version 180910.0.17763.9376
Windows 10 Version 21H210.0.19044.7807
Windows 10 Version 22H210.0.19045.7807
Windows 11 version 23H210.0.22631.7652
Windows 11 Version 23H210.0.22631.7652

Every device with Microsoft Windows needs the update.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 13 Oct 2026, within a day of it being made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 16 Oct 2026 to fix it.[1]

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 10%. That’s in the top 5% of the flaws it scores.[4]

CISA assesses it as not automatable: each attack takes some work.

CISA doesn’t say who was attacked, or how.

Fix

Microsoft has published a fix or advice.[3] CISA’s required action: “Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes).”[1]

  1. Update Microsoft Windows now.On Windows: Settings, Windows Update, Check for updates, then restart. Office updates come the same way, or from any Office app: File, Account, Update Options. Then turn on automatic updates, so the next fix arrives on its own.
  2. Check you’re on 154.0.4258.62 or later.Fixed in version 154.0.4258.62, 20260925.100, 10.0.14393.9612 and 10.0.17763.9376 and others. Anything older is what attackers are going after.
  3. If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 8.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at 10%.[4]

See also

Other Microsoft Windows flaws

Other command injection flaws

Added the same day

  • CVE-2026-104935, Ivanti Connect Secure: authentication bypass by spoofing ·

Every Microsoft flaw on CISA’s list · Everything added in October 2026

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Microsoft Windows Command Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 13 Oct 2026.
  2. ^ National Institute of Standards and Technology. “CVE-2026-96951 Detail”. National Vulnerability Database, published 13 Oct 2026.
  3. ^ Microsoft. Advisories and fixes: msrc.microsoft.com, msrc.microsoft.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.098, percentile 95.5, 31 Oct 2026.
  5. CVE Program. “CVE-2026-96951”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.