Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
-
AccessDeliver crafted Access file via email/web
-
DeliveryVictim opens malicious database
-
ExploitTrigger heap buffer overflow in parser
-
ExecutionExecute arbitrary code as user
-
ImpactEstablish foothold on host
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Heap buffer bounds checking
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires a victim to open an attacker-crafted Microsoft Access file (UI:R in the CVSS vector), so it depends on user interaction and a working social-engineering delivery (email attachment, download, or shared file). The Microsoft Access component of Office must be installed and used to open the file; environments without Access deployed are not exposed. No authentication is required of the attacker (PR:N), and attack complexity is low (AC:L), but the user-interaction gate means this is not remotely triggerable against an idle system and is not self-propagating. Code executes in the context/privileges of the user who opens the file, not automatically as SYSTEM. |
| Impact | This is a credible mid-to-high priority issue, but not a drop-everything emergency based on current signals. The CVSS 3.1 base score is 8.8 (High) with an AV:N/AC:L/PR:N/UI:R vector: network attack vector, low complexity, no privileges required, but user interaction IS required - the classic Microsoft Office pattern where a victim must open a maliciously crafted Access database/file. Impact is severe (C:H/I:H/A:H, Scope:Unchanged), consistent with arbitrary code execution in the user's security context. No EPSS probability score was provided in the input, so exploitation likelihood cannot be quantified. KEV status is not indicated (not listed), and no proof-of-concept is referenced, so this is best treated as no public exploit identified at time of analysis rather than active exploitation. No SSVC decision data was supplied. The key tension to flag: the headline '8.8 network RCE' reads more dangerous than the practical reality, because UI:R means exploitation hinges on social engineering (getting a target to open a hostile file) - it is not wormable or self-propagating. There is no conflict between the CVSS vector and the description; both agree on network-delivered, user-interaction-gated code execution. Missing data: EPSS score and any vendor exploitability assessment from Microsoft's MSRC advisory were not included in the provided input and should be verified directly. |
| Exploit ScenarioDerived | An attacker emails or hosts a malicious Microsoft Access database file and lures a victim into opening it. When the file is parsed, a heap-based buffer overflow (CWE-122) is triggered, corrupting heap memory to achieve arbitrary code execution in the context of the user who opened the file. No public proof-of-concept was referenced in the provided data, and the required user interaction (UI:R) makes this dependent on successful social engineering. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAIv1 – Oct 13, 2026
Heap-based buffer overflow in Microsoft Office Access allows an unauthenticated remote attacker to execute arbitrary code in the security context of the user who opens a crafted Access database file. Exploitation is gated by user interaction (UI:R) - the victim must open an attacker-supplied file delivered by email, web download, or shared location - with low attack complexity (AC:L) and no credentials required from the attacker (PR:N), and code runs as the invoking user rather than as SYSTEM. Rated 8.8 (C:H/I:H/A:H); no public exploit code and no confirmed active exploitation were identified at time of analysis, and environments that do not install or use Access are not exposed.
RemediationAI
Patch status per the provided data: no vendor-released patch version is identified at time of analysis; the authoritative fix information is Microsoft's update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-102850, which should be checked and applied (Microsoft Update / Office update channel) as soon as a fixed build is published. Until then, prioritize compensating controls: remove or do not deploy the Access component where it is unused by excluding it from the Office installation via the Office Deployment Tool or Group Policy - effective, but it breaks any internal Access-based database applications; force Protected View for files originating from the internet and for untrusted locations and enable File Block settings for legacy Access formats - reduces exposure but adds prompt/latency friction and can be bypassed if users unblock files; deploy Microsoft Defender for Endpoint attack surface reduction rules such as blocking Office applications from creating child processes and blocking Win32 API calls from Office macros - requires Defender coverage and can generate false positives for legitimate automation; and block .accdb, .accde, .accdr, .accdt, .mdb, .mde, .ade, and .adp attachments and downloads at email and web gateways - highly effective against the delivery vector at the cost of breaking legitimate database file exchange, for which a quarantined submission workflow should be offered. Monitoring for unusual child processes spawned by Access remains useful given there is no public exploit code identified at time of analysis, and the issue should be treated as a credible mid-to-high priority rather than an emergency-tier response based on current signals.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The root cause class is CWE-122, a heap-based buffer overflow, inside the parsing path Microsoft Office Access uses when opening an Access database file. Access stores data in containers handled by the ACE/Jet database engine; attacker-controlled length, count, and offset fields in the file structures (tables, indexes, object metadata, and other stream data) drive heap allocations and the size of subsequent copy operations, and a missing bounds check allows those copies to overrun the allocation. Overwriting heap metadata or adjacent objects can subvert control flow in the process that opened the file, which is the Office process running as the current user. The CVSS 3.1 vector AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H confirms a network-delivered, unauthenticated attack that is nonetheless conditioned on victim file opening, with unchanged scope - impact stays within the victim user's privileges and the bug is not self-propagating. No CPE enumeration was provided in the intelligence feed, so exact affected builds and product identifiers must be confirmed against the Microsoft advisory.
Know when 365 Apps gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
File is delivered over the network (AV:N) and needs no attacker privileges (PR:N), but the victim must open it (UI:R); successful memory corruption yields full code execution (C/I/A:H).
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code over a network.
Executive ViewAI
A high-severity memory corruption flaw in Microsoft Access (CVE-2026-102850) lets an attacker run arbitrary code as the signed-in user when a crafted Access database file is opened, meaning a single emailed or downloaded file could hand an attacker the same access rights as the employee who opened it. Only staff with Access installed and who handle incoming .accdb files are exposed, but those users often sit in finance, operations, and engineering roles with access to sensitive data. Because no vendor patch is currently available, the organization must rely on temporary file-handling restrictions and user awareness to reduce exposure until Microsoft releases a fix.
No vendor-released patch identified at time of analysis. Interim mitigations: uninstall or do not install Microsoft Access where not business-required; block .accdb/.accde/.accdr/.accdt files at email and web gateways; enforce Office Protected View and Attack Surface Reduction rules (block Office child processes and obfuscated script execution); restrict access to untrusted shared locations; and monitor EDR for Office processes spawning unexpected executables. No public exploit identified at time of analysis.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.
Microsoft Outlook Remote Code Execution Vulnerability. Rated critical severity (CVSS 9.8), this vulnerability is remotel
Microsoft Excel Security Feature Bypass Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authenti
Microsoft Outlook Security Feature Bypass Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely
Microsoft Publisher Security Feature Bypass Vulnerability. Rated high severity (CVSS 7.3), this vulnerability is low att
Microsoft Office contains a security feature bypass (CVE-2026-21509, CVSS 7.8) where reliance on untrusted inputs in sec
Microsoft Office Word contains a security decision bypass (CVE-2026-21514, CVSS 7.8) through reliance on untrusted input
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vu
Microsoft Office Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentic
Microsoft Excel Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentica
Use-after-free vulnerability in Microsoft Office Word that allows local, unauthenticated attackers to execute arbitrary
Microsoft Excel Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely expl
Microsoft Office Elevation of Privilege Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is low attack
EUVD-2026-99026
GHSA-c9xw-g7fp-6m53
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB