CVE-2017-11826 — Microsoft Office Remote Code Execution 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 — portal.msrc.microsoft.com (NIST National Vulnerability Database)

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Mar 24, 2022 — passed 1666 day(s) ago

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 Office, Microsoft Office Compatibility Pack, Microsoft Office Online Server…).
2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
3. Apply the fixed version or the patch documented under Remediation.
4. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
5. EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
6. Search available logs for exploit probes matching the vulnerability class (memory corruption), 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-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

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.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 81.33%

Detection

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

• Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
• Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
• Hunt retroactively in logs from before Mar 3, 2022 (KEV listing): exploitation may have started earlier.

Timeline

What happened to this CVE, newest first.

• 2026
• Affected products added · microsoft corporation/microsoft office
  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
• Fix documented
  Oct 13, 2026 · NIST National Vulnerability Database
• Affected products added · microsoft/office compatibility pack, microsoft/office online server, microsoft/office web apps server, microsoft/office
  Oct 13, 2026 · NIST National Vulnerability Database
• CVSS changed · 7.8
  Oct 13, 2026 · NIST National Vulnerability Database
• Source status changed · → Analyzed
  Oct 13, 2026 · NIST National Vulnerability Database
• Added to CISA KEV (detected)
  Oct 13, 2026 · CISA Known Exploited Vulnerabilities
• Record created in this database
  Oct 13, 2026 · CISA Known Exploited Vulnerabilities
• 2022
• Added to CISA KEV catalog
  Mar 2, 2022 · CISA
• 2017
• CVE published
  Oct 13, 2017 · microsoft

Source activity

Repeated readings are counted rather than listed.

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

References

11 on the record

• portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11826
  Patch, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
• www.cisa.gov/known-exploited-vulnerabilities-catalog
  US Government Resource, NIST National Vulnerability Database
• www.securityfocus.com/bid/101219
  Broken Link, Third Party Advisory, VDB Entry, vdb-entry, x_refsource_BID, NIST National Vulnerability Database
• github.com/advisories/GHSA-4qcg-gx82-4h36
  GitHub Security Advisories
• www.tarlogic.com/en/blog/exploiting-word-cve-2017-11826/
  Exploit, Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
• nvd.nist.gov/vuln/detail/CVE-2017-11826
  GitHub Security Advisories
• securingtomorrow.mcafee.com/mcafee-labs/analyzing-microsoft-office-zero-day-exploit-cve-2017-1182
  Broken Link, Technical Description, Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
• securingtomorrow.mcafee.com/mcafee-labs/analyzing-microsoft-office-zero-day-exploit-cve-2017-1182
  GitHub Security Advisories
• 0patch.blogspot.com/2017/11/0patching-pretty-nasty-microsoft-word.html
  Exploit, x_refsource_MISC, NIST National Vulnerability Database
• www.securitytracker.com/id/1039541
  Broken Link, Third Party Advisory, VDB Entry, vdb-entry, x_refsource_SECTRACK, NIST National Vulnerability Database
• www.tarlogic.com/en/blog/exploiting-word-cve-2017-11826
  GitHub Security Advisories

Elsewhere on this site

Related CVEs (same products)

• Medium CVE-2026-97783 Microsoft Office SharePoint Spoofing Vulnerability 2d
• High CVE-2026-97780 Microsoft Office Excel Remote Code Execution Vulnerability 2d
• Medium CVE-2026-97782 Microsoft Office SharePoint Tampering Vulnerability 2d
• High CVE-2026-97776 Microsoft Office Excel Remote Code Execution Vulnerability 2d
• High CVE-2026-97777 Microsoft Office Excel Remote Code Execution Vulnerability 2d
• High CVE-2026-97775 Microsoft Office Excel Remote Code Execution Vulnerability 2d

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-2017-11826 is "Microsoft Office Remote Code Execution Vulnerability", rated High. It affects Office (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.8 describes technical severity. EPSS 81.33% 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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