CVE-2026-96951 — Microsoft Windows Command Injection Vulnerability

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

• Documented patch — msrc.microsoft.com (NIST National Vulnerability Database)

CISA required action CISA

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). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

US federal deadline: Oct 16, 2026 — due in 1 day(s)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

1. Identify exposed assets running the affected vendor/product/version combinations (Microsoft Outlook Web, Microsoft Outlook.com, Microsoft Windows 10 1607…).
2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
4. Apply the fixed version or the patch documented under Remediation.
5. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
6. Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-77 · Command Injection

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

• Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
• Look for parameters with command/query metacharacters and unexpected child processes of the service.
• Hunt retroactively in logs from before Oct 13, 2026 (KEV listing): exploitation may have started earlier.

Timeline

What happened to this CVE, newest first.

• 2026
• Affected products removed · 1
  Oct 14, 2026 · NIST National Vulnerability Database
• Affected products added · microsoft/outlook web
  Oct 14, 2026 · NIST National Vulnerability Database
• Fix documented
  Oct 14, 2026 · NIST National Vulnerability Database
• Affected products added · microsoft/outlook, microsoft/windows 10 1607, microsoft/windows 10 1809, microsoft/windows 10 21h2, microsoft/windows 10
  Oct 14, 2026 · NIST National Vulnerability Database
• Source status changed · Undergoing Analysis → Analyzed
  Oct 14, 2026 · NIST National Vulnerability Database
• SSVC assessment updated
  Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
• Added to CISA KEV (detected)
  Oct 13, 2026 · CISA Known Exploited Vulnerabilities
• Source status changed · Awaiting Analysis → Undergoing Analysis
  Oct 13, 2026 · NIST National Vulnerability Database
• Affected products added · microsoft/outlook.com, microsoft/windows 10 version 1607, microsoft/windows 10 version 1809, microsoft/windows 10 versio
  Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
• SSVC assessment updated
  Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
• Record published
  Oct 13, 2026
• CVSS changed · 8.8
  Oct 13, 2026 · NIST National Vulnerability Database
• Source status changed · → Awaiting Analysis
  Oct 13, 2026 · NIST National Vulnerability Database
• Record created in this database
  Oct 13, 2026 · NIST National Vulnerability Database
• CVE published
  Oct 13, 2026 · microsoft
• Added to CISA KEV catalog
  Oct 12, 2026 · CISA

Source activity

Repeated readings are counted rather than listed.

• 2× References added · Oct 13, 2026 – Oct 14, 2026
• 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

• msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96951
  vendor-advisory, patch, Patch, Vendor Advisory, NIST National Vulnerability Database
• www.cisa.gov/known-exploited-vulnerabilities-catalog
  US Government Resource, NIST National Vulnerability Database
• nvd.nist.gov/vuln/detail/CVE-2026-96951
  GitHub Security Advisories
• github.com/advisories/GHSA-hjr5-mppg-mjq7
  GitHub Security Advisories

Elsewhere on this site

Related CVEs (same products)

• Medium CVE-2026-97844 Role: DNS Server Information Disclosure Vulnerability 1d
• Medium CVE-2026-97841 Role: DNS Server Information Disclosure Vulnerability 1d
• Medium CVE-2026-97839 Role: DNS Server Information Disclosure Vulnerability 1d
• Medium CVE-2026-97840 Role: DNS Server Information Disclosure Vulnerability 1d
• Medium CVE-2026-97842 Role: DNS Server Information Disclosure Vulnerability 1d
• Medium CVE-2026-97843 Role: DNS Server Information Disclosure Vulnerability 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

• No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
• No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
• No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-96951 is "Microsoft Windows Command Injection Vulnerability", rated High. It affects Outlook Web (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 8.8 describes technical severity. EPSS 1.51% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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