CVE-2026-108437
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Published Oct 15, 2026 · corrected/updated Oct 16, 2026 · Microsoft Microsoft 365 · evidence confidence high
Affected Microsoft products: Microsoft Office LTSC 2024 for 32-bit editions, Microsoft Office LTSC 2024 for 64-bit editions, Microsoft Office LTSC 2021 for 32-bit editions, Microsoft Office LTSC 2021 for 64-bit editions.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-108437 is a high public vulnerability record for Microsoft Microsoft 365. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether Microsoft Microsoft 365 is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: Microsoft Office LTSC 2021 for 32-bit editions; Microsoft Office LTSC 2021 for 64-bit editions; Microsoft Office LTSC 2024 for 32-bit editions; Microsoft Office LTSC 2024 for 64-bit editions. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 8.8, EPSS 0.4%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-122. Sources contributing to this record: cve_org, epss, msrc, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 15, 2026 · NIST NVD
Detected
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Oct 16, 2026 · NIST NVD
Updated
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Affected
- microsoft Microsoft Office LTSC 2021 for 32-bit editionsversion unspecified
- microsoft Microsoft Office LTSC 2021 for 64-bit editionsversion unspecified
- microsoft Microsoft Office LTSC 2024 for 32-bit editionsversion unspecified
- microsoft Microsoft Office LTSC 2024 for 64-bit editionsversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-108437
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-108437
30-day exploitation probability 0.4%
first.org - Microsoft Security Update GuideVendor advisoryCVE-2026-108437
Microsoft Office LTSC 2024 for 32-bit editions, Microsoft Office LTSC 2024 for 64-bit editions, Microsoft Office LTSC 2021 for 32-bit editions, Microsoft Office LTSC 2021 for 64-bit editions
msrc.microsoft.com - NIST NVDVulnerability recordCVE-2026-108437
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
nvd.nist.gov