Cyber Resilience

CVE-2026-35436

Microsoft Office Long Term Servicing Channel 2021 … 2024

Published
12 May 2026
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0022 13th percentile
Risk Priority 59 floored blend · peak EPSS

Summary

CVE-2026-35436 is a high-severity Insufficient Granularity of Access Control (CWE-1220) vulnerability in Microsoft Office Long Term Servicing Channel. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Services File Permissions Weakness (T1574.010); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1574.010 Services File Permissions Weakness Stealth
Adversaries may execute their own malicious payloads by hijacking the binaries used by services.
T1078 Valid Accounts Stealth
Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1556 Modify Authentication Process Defense Impairment
Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-36569Same product: Microsoft 365 Apps
CVE-2023-33149Same product: Microsoft 365 Apps
CVE-2024-38021Same product: Microsoft 365 Apps
CVE-2024-49059Same product: Microsoft 365 Apps
CVE-2023-33152Same product: Microsoft 365 Apps
CVE-2023-36767Same product: Microsoft 365 Apps
CVE-2026-50502Same vendor: Microsoft
CVE-2024-26246Same vendor: Microsoft
CVE-2024-43616Same product: Microsoft 365 Apps
CVE-2023-33153Same product: Microsoft 365 Apps

Affected Assets

microsoft
365 apps
all versions
microsoft
office
2019
microsoft
office long term servicing channel
2021, 2024

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 4 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V16.4.2
  • V8.4.2
  • V11.7.1
  • V13.2.4

Mitigating Controls (NIST 800-53 r5) AI

Least privilege explicitly demands that only the minimum necessary accesses are granted, eliminating the broad permissions that define this weakness.

AC-24 requires access decisions to be applied precisely and unambiguously to every request, structurally blocking insufficiently granular policies.

AC-3 requires enforcement of authorizations according to policy, directly compelling sufficiently granular rules so broad allowances cannot be introduced.

AC-4 enforces approved information flows with explicit source/destination rules, preventing overly coarse access policies from being deployed.

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.

PR.IR-01 mostly match
prevents

PR.IR-01's segmentation + zero-trust rules directly enforce minimum-necessary access at network boundaries, removing most instances of overly broad policy; CWE-1220 can still exist in application-layer or intra-segment controls that this single outcome does not address.

PR.PS-06 partial match
prevents

PR.PS-06's general SDLC practices can surface granularity issues during design/review (partial prevention) but do not specifically target access-control policy breadth, so they remove only part of CWE-1220's risk.

DE.AE-06 none match
degrades

CWE-1220 permits unauthorized access to sensitive assets but neither prevents nor impairs the delivery of adverse-event information to authorized recipients.

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.

degrades

Directly requires information-access restriction at the level of individual assets and operations, addressing the granularity gap.

prevents

Establishes the overarching access-control policy whose granularity directly determines whether the weakness exists.

prevents

Defines the assignment and review of access rights; insufficient granularity in those rights is the root of CWE-1220.

prevents

Specifies management of privileged access rights, where overly broad privileges are a common manifestation of the weakness.

none

Limits use of privileged utilities; overly coarse access rules can still allow unauthorized utility access.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Windows Server 2016 (1 rule)
  • V-225025 Local accounts with blank passwords must be restricted to prevent access from the network. prevents CWE-1220
Windows Server 2022 (1 rule)
  • V-254446 Windows Server 2022 must prevent local accounts with blank passwords from being used from the network. prevents CWE-1220

References