CVE-2026-78512high8.8

Microsoft Office Word Remote Code Execution Vulnerability

Impact

A numeric truncation error in Microsoft Office Word may allow an attacker to execute code. Affected versions include Microsoft 365 Apps for Enterprise, Microsoft Office 2016, and others.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Affected packages

This source has no supported package-version data for matching. You can read the advisory here, but this record alone cannot power a dependency check.

Affected products

Vendor version evidence. Product records are separate from automatic dependency matching.

Microsoft · microsoft

Microsoft 365 Apps for Enterprise

1 range

microsoft version evidence

Platforms: 32-bit Systems, x64-based Systems

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affected

16.0.1 → before 16.0.20326.20138

custom versions

Other versions: unknown

Microsoft · microsoft

Microsoft Office 2016

1 range

microsoft version evidence

Platforms: 32-bit Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

16.0.0 → before 16.0.5569.1002

custom versions

Other versions: unknown

Microsoft · microsoft

Microsoft Office 2019

1 range

microsoft version evidence

Platforms: 32-bit Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

19.0.0 → before 16.0.10417.20207

custom versions

Other versions: unknown

Microsoft · microsoft

Microsoft Office 365 for Mac

1 range

microsoft version evidence

Check a product version

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affected

1.0.0 → before 16.113.26091433

custom versions

Other versions: unknown

Microsoft · microsoft

Microsoft Office LTSC 2021

1 range

microsoft version evidence

Platforms: 32-bit Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

16.0.1 → before 16.0.14334.20906

custom versions

Other versions: unknown

Microsoft · microsoft

Microsoft Office LTSC 2024

1 range

microsoft version evidence

Platforms: 32-bit Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

16.0.0 → before 16.0.17932.20976

custom versions

Other versions: unknown

Microsoft · microsoft

Microsoft Office LTSC for Mac 2021

1 range

microsoft version evidence

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

16.0.1 → before 16.113.26091433

custom versions

Other versions: unknown

Microsoft · microsoft

Microsoft Office LTSC for Mac 2024

1 range

microsoft version evidence

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

16.0.0 → before 16.113.26091433

custom versions

Other versions: unknown

Original source description

Numeric truncation error in Microsoft Office Word allows an unauthorized attacker to execute code over a network.

Inside the record

Evidence available

Package identity · not supplied

Version evidence

Remediation guidance · not supplied

Weakness classification

Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-78512

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-197 ↗

CWE-197: Numeric Truncation Error

microsoft

CWE-122 ↗

CWE-122: Heap-based Buffer Overflow

microsoft

Environment requirements

These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.

microsoft · platform conditions

Any condition may hold

Vulnerable product

cpe:2.3:a:microsoft:office_2019:*:*:*:*:*:*:*:*

From (inclusive): 19.0.0

After:

Through (inclusive):

Before: 16.0.10417.20207

Vulnerable product

cpe:2.3:a:microsoft:365_apps:*:*:*:*:enterprise:*:*:*

From (inclusive): 16.0.1

After:

Through (inclusive):

Before: 16.0.20326.20138

Vulnerable product

cpe:2.3:a:microsoft:office_macos_2021:*:*:*:*:*:long_term_servicing_channel:*:*

From (inclusive): 16.0.1

After:

Through (inclusive):

Before: 16.113.26091433

Vulnerable product

cpe:2.3:a:microsoft:office_2021:*:*:*:*:long_term_servicing_channel:*:*:*

From (inclusive): 16.0.1

After:

Through (inclusive):

Before: 16.0.14334.20906

Vulnerable product

cpe:2.3:a:microsoft:office_2024:*:*:*:*:long_term_servicing_channel:*:*:*

From (inclusive): 16.0.0

After:

Through (inclusive):

Before: 16.0.17932.20976

Vulnerable product

cpe:2.3:a:microsoft:office_macos_2024:*:*:*:*:*:long_term_servicing_channel:*:*

From (inclusive): 16.0.0

After:

Through (inclusive):

Before: 16.113.26091433

Vulnerable product

cpe:2.3:a:microsoft:office_2016:*:*:*:*:*:*:x86:*

From (inclusive): 16.0.0

After:

Through (inclusive):

Before: 16.0.5569.1002

Vulnerable product

cpe:2.3:a:microsoft:office_365:*:*:*:*:*:macos:*:*

From (inclusive): 1.0.0

After:

Through (inclusive):

Before: 16.113.26091433

Original applicability statements

[
  {
    "nodes": [
      {
        "operator": "OR",
        "negate": false,
        "cpeMatch": [
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:office_2019:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "19.0.0",
            "versionEndExcluding": "16.0.10417.20207"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:365_apps:*:*:*:*:enterprise:*:*:*",
            "versionStartIncluding": "16.0.1",
            "versionEndExcluding": "16.0.20326.20138"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:office_macos_2021:*:*:*:*:*:long_term_servicing_channel:*:*",
            "versionStartIncluding": "16.0.1",
            "versionEndExcluding": "16.113.26091433"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:office_2021:*:*:*:*:long_term_servicing_channel:*:*:*",
            "versionStartIncluding": "16.0.1",
            "versionEndExcluding": "16.0.14334.20906"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:office_2024:*:*:*:*:long_term_servicing_channel:*:*:*",
            "versionStartIncluding": "16.0.0",
            "versionEndExcluding": "16.0.17932.20976"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:office_macos_2024:*:*:*:*:*:long_term_servicing_channel:*:*",
            "versionStartIncluding": "16.0.0",
            "versionEndExcluding": "16.113.26091433"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:office_2016:*:*:*:*:*:*:x86:*",
            "versionStartIncluding": "16.0.0",
            "versionEndExcluding": "16.0.5569.1002"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:office_365:*:*:*:*:*:macos:*:*",
            "versionStartIncluding": "1.0.0",
            "versionEndExcluding": "16.113.26091433"
          }
        ]
      }
    ]
  }
]

Contributing organizations · 2

microsoft

Assigning organization

2026-10-30

CISA-ADP

Additional data publisher

2026-09-09

What changed

Follow changes

No substantive changes have been recorded here yet. History starts when cve.new observes a change after tracking is enabled; earlier edits are not reconstructed.

Large field values are marked as truncated previews. Original source snapshots remain retained.

References

1 sources

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78512

vendor-advisorymicrosoft

Priority and evidence

Not in CISA KEVNo package fix recorded

KEV coverage does not rule out exploitation.

KEV checked 31/10/2026, 15:15:33 UTC

microsoft · CVSS:3.1 · 8.8

Assessment vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Reading the signals

Severity · CVSS: Technical impact and attack conditions. The headline is the highest imported catalog score; sources may disagree.
Observed exploitation · KEV: An absent or unavailable KEV listing does not establish that exploitation has not occurred.
Predicted exploitation · EPSS: 0.82% estimated probability in the next 30 days. 2026-10-30 · FIRST EPSS.

CISA-ADP · SSVC

CISA Coordinator · 2026-09-09

Exploitation: none
Automatable: no
Technical Impact: total

SSVC describes the publisher’s decision context. Your organization’s exposure and priorities may differ.

Record details

Published: 08/09/2026, 17:18:33 UTC
Modified: 30/10/2026, 21:56:50 UTC
Last imported by cve.new: 30/10/2026, 22:46:34 UTC
Aliases: None recorded

Source evidence

Request a correction or dispute

Start with the assigning organization for this record. Include the CVE ID, the disputed information, and supporting evidence. A dispute does not itself reject a record.

Find the responsible CNA →Official dispute and escalation process ↗

CVE CVE-2026-78512

Enrichment coverage

NVDAvailable

Checked 31/10/2026, 03:40:31 UTC

GHSAAvailable

Checked 31/10/2026, 03:40:30 UTC

EUVDAvailable

Checked 31/10/2026, 03:40:31 UTC

EPSSAvailable

Checked 31/10/2026, 03:40:31 UTC

Additional source evidence

GitHub Advisory Database · GHSA-wmm4-h5xq-67rx

CVSS 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Checked 31/10/2026, 03:40:30 UTC

FIRST EPSS · CVE-2026-78512

EPSS 0.82% probability of exploitation in the next 30 days. Percentile: 57.17% · 2026-10-30

Checked 31/10/2026, 03:40:31 UTC

ENISA EUVD · EUVD-2026-73818

CVSS 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Checked 31/10/2026, 03:40:31 UTC

NVD · CVE-2026-78512

CVSS 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Checked 31/10/2026, 03:40:31 UTC

Sponsored by MoxsoBuild security habits with adaptive training and phishing simulations.View as JSON

Microsoft Office Word Remote Code Execution Vulnerability

Impact

Affected packages

Affected products

Microsoft 365 Apps for Enterprise

affected

unaffected

unknown

Microsoft Office 2016

affected

unaffected

unknown

Microsoft Office 2019

affected

unaffected

unknown

Microsoft Office 365 for Mac

affected

unaffected

unknown

Microsoft Office LTSC 2021

affected

unaffected

unknown

Microsoft Office LTSC 2024

affected

unaffected

unknown

Microsoft Office LTSC for Mac 2021

affected

unaffected

unknown

Microsoft Office LTSC for Mac 2024

affected

unaffected

unknown

Original source description

Inside the record

Evidence available

Original records

Underlying weaknesses

Environment requirements

What changed

References