CVE-2025-21395: Microsoft Access Remote Code Execution Vulnerability
CVE-2025-21395 is a remote code execution vulnerability in Microsoft Access, rated Important by Microsoft, with a CVSS 3.1 base score of 7.8 (High). An attacker can exploit it by an attacker with local access, without any privileges and only if a user takes an action. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. It was publicly disclosed before the fix was released. The EPSS model estimates a 1.06% probability of exploitation activity in the next 30 days, higher than 65% of all scored vulnerabilities. Microsoft released the fix on 14 January 2025 in the January 2025 Patch Tuesday, delivered through 1 security update (KB5002688). It affects 10 products in 1 product family (Microsoft Office).
Key facts
- CVE ID
- CVE-2025-21395
- Severity
- High CVSS 7.8
- Microsoft severity
- Important
- Impact
- Remote Code Execution
- Exploited in the wild
- No
- Publicly disclosed
- Yes
- Exploitation likelihood
- Less Likely
- Weakness
- CWE-122
- EPSS
- 1.06% (percentile 65%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- January 2025 Patch Tuesday
- Product families
- Microsoft Office
CVSS score and vector
Microsoft scores CVE-2025-21395 at 7.8 (temporal 6.8) using CVSS 3.1. Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Frequently asked questions (Microsoft)
According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution?
The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally.
For example, when the score indicates that the Attack Vector is Local and User Interaction is Required, this could describe an exploit in which an attacker, through social engineering, convinces a victim to download and open a specially crafted file from a website which leads to a local attack on their computer.
How does the update protect against this vulnerability?
The update blocks potentially malicious extensions from being sent in an email.
Which types of extensions are blocked?
The following extensions which will be blocked:
- accdb
- accde
- accdw
- accdt
- accda
- accdr
- accdu
Is there any notification indicating an email contained a blocked extension?
The email recipient will get a notification that there was an attachment but it cannot be accessed.
Is the Preview Pane an attack vector for this vulnerability?
No, the Preview Pane is not an attack vector.
Affected products (10)
Microsoft Office
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft Office 2019 for 32-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office 2019 for 64-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft 365 Apps for Enterprise for 32-bit Systems | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office LTSC 2021 for 64-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office LTSC 2021 for 32-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office LTSC 2024 for 32-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office LTSC 2024 for 64-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Access 2016 (32-bit edition) | KB5002688 | Security Update | 16.0.5487.1000 | Maybe |
| Microsoft Access 2016 (64-bit edition) | KB5002688 | Security Update | 16.0.5487.1000 | Maybe |
Security updates (1)
- KB5002688 (Security Update)
NIST NVD data
- NVD status
- Analyzed
- NVD CVSS
- 7.8 (HIGH)
- NVD weakness
- CWE-122
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| 365 apps (x64) | all listed versions |
| 365 apps (x86) | all listed versions |
| access 2016 | all listed versions |
| office 2019 (x64) | all listed versions |
| office 2019 (x86) | all listed versions |
| office long term servicing channel 2021 (x64) | all listed versions |
| office long term servicing channel 2021 (x86) | all listed versions |
| office long term servicing channel 2024 (x64) | all listed versions |
| office long term servicing channel 2024 (x86) | all listed versions |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21395 (Patch, Vendor Advisory)
Acknowledgments
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. | |
| 1.1 | Added an FAQ to indicate that the Preview Pane is not affected for this CVE. This is an informational change only. | |
| 2.0 | To comprehensively address CVE-2025-21395 Microsoft has released secuirty update 5002688 for supported editions of Microsoft Access 2016. Microsoft recommends that customers install the update to be fully protected from the vulnerability. Customers whose systems are configured to receive automatic updates do not need to take any further action. |