Security Resilience

CVE-2026-70300

Microsoft 365 Apps

Published
13 October 2026
Modified
14 October 2026
Patch / advisory
View advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0098 61th percentile
Risk Priority 73 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-70300 is a critical-severity Untrusted Pointer Dereference (CWE-822) vulnerability in Microsoft 365 Apps. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 39% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Untrusted pointer dereference in Microsoft Office Word allows an unauthorized attacker to execute code over a network.

CWE(s)
CWE-822

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001 Data Obfuscation Command And Control
Adversaries may obfuscate command and control traffic to make it more difficult to detect.
attack.mitre.org →
T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1016 System Network Configuration Discovery Discovery
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
attack.mitre.org →
T1016.001 Internet Connection Discovery Discovery
Adversaries may check for Internet connectivity on compromised systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-45643Same product: Microsoft 365 Apps
CVE-2026-64910Same product: Microsoft 365 Apps
CVE-2026-68810Same product: Microsoft 365 Apps
CVE-2026-45471Same product: Microsoft 365 Apps
CVE-2026-55138Same product: Microsoft 365 Apps
CVE-2026-55136Same product: Microsoft 365 Apps
CVE-2026-48580Same product: Microsoft 365 Apps
CVE-2026-20956Same product: Microsoft 365 Apps
CVE-2025-21363Same product: Microsoft 365 Apps
CVE-2026-33114Same product: Microsoft 365 Apps

Affected Assets

microsoft
365 apps
all versions
microsoft
office 2021
all versions
microsoft
office 2024
all versions

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation partial match

Developer testing and evaluation can discover instances where untrusted data is turned into a pointer and dereferenced.

SI-10 Information Input Validation partial match

Validating all information inputs stops untrusted values from being accepted and converted into dereferenceable pointers.

SI-16 Memory Protection partial match

Memory-protection mechanisms limit the damage from an invalid pointer dereference without stopping the root coding flaw.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

DE.CM-09 partial match
blocks

Runtime monitoring of software and data can detect adverse events resulting from exploitation of the weakness.

ID.RA-01 partial match
blocks

Vulnerability identification processes can discover instances of this weakness via code review or scanning.

PR.PS-06 partial match
blocks

Secure SDLC practices directly prevent introduction of untrusted pointer handling during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References