Multiple vulnerabilities in Microsoft Excel
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 6 |
| CVE-ID | CVE-2025-21386 CVE-2025-21387 CVE-2025-21390 CVE-2025-21383 CVE-2025-21394 CVE-2025-21381 |
| CWE-ID | CWE-416 CWE-122 CWE-125 CWE-822 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software |
Office Online Server Server applications / Other server solutions Microsoft Office Client/Desktop applications / Office applications Microsoft Excel Client/Desktop applications / Office applications Microsoft 365 Apps for Enterprise Client/Desktop applications / Office applications Microsoft Office LTSC Client/Desktop applications / Other client software |
| Vendor | Microsoft |
Security Bulletin
This security bulletin contains information about 6 vulnerabilities.
1) Use-after-free
EUVDB-ID: #VU103806
Risk: High
CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]
CVE-ID: CVE-2025-21386
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the target system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsOffice Online Server: All versions
Microsoft Office: 2019
Microsoft Excel: 2016
Microsoft Office LTSC: 2021 - 2024 for Mac
Microsoft 365 Apps for Enterprise: 32-bit Systems - 64-bit Systems
CPE2.3- cpe:2.3:a:microsoft:office_online_server:*:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office:*:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_excel:*:*:*:*:*:microsoft_office:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:for Mac:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2024:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:32-bit_Systems:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:64-bit_Systems:*:*:*:*:*:*:*
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21386
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Use-after-free
EUVDB-ID: #VU103811
Risk: High
CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]
CVE-ID: CVE-2025-21387
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the target system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsOffice Online Server: All versions
Microsoft Office: 2019
Microsoft Excel: 2016
Microsoft Office LTSC: 2021 - 2024 for Mac
Microsoft 365 Apps for Enterprise: 32-bit Systems - 64-bit Systems
CPE2.3- cpe:2.3:a:microsoft:office_online_server:*:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:for Mac:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2024:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:32-bit_Systems:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:64-bit_Systems:*:*:*:*:*:*:*
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21387
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Heap-based buffer overflow
EUVDB-ID: #VU103810
Risk: High
CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]
CVE-ID: CVE-2025-21390
CWE-ID:
CWE-122 - Heap-based Buffer Overflow
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file, trigger a heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsOffice Online Server: All versions
Microsoft Office: 2019
Microsoft Excel: 2016
Microsoft Office LTSC: 2021 - 2024 for Mac
Microsoft 365 Apps for Enterprise: 32-bit Systems - 64-bit Systems
CPE2.3- cpe:2.3:a:microsoft:office_online_server:*:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:for Mac:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2024:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:32-bit_Systems:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:64-bit_Systems:*:*:*:*:*:*:*
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21390
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
4) Out-of-bounds read
EUVDB-ID: #VU103809
Risk: Medium
CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2025-21383
CWE-ID:
CWE-125 - Out-of-bounds read
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition in Microsoft Excel. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger an out-of-bounds read error and read contents of memory on the system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsMicrosoft Office: 2019
Microsoft Excel: 2016
Microsoft Office LTSC: 2021 - 2024 for Mac
Microsoft 365 Apps for Enterprise: 32-bit Systems - 64-bit Systems
CPE2.3- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:for Mac:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2024:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:32-bit_Systems:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:64-bit_Systems:*:*:*:*:*:*:*
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21383
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
5) Use-after-free
EUVDB-ID: #VU103808
Risk: High
CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]
CVE-ID: CVE-2025-21394
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsOffice Online Server: All versions
Microsoft Office: 2019
Microsoft Excel: 2016
Microsoft Office LTSC: 2021 - 2024 for Mac
Microsoft 365 Apps for Enterprise: 32-bit Systems - 64-bit Systems
CPE2.3- cpe:2.3:a:microsoft:office_online_server:*:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:for Mac:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2024:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:32-bit_Systems:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:64-bit_Systems:*:*:*:*:*:*:*
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21394
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
6) Untrusted Pointer Dereference
EUVDB-ID: #VU103807
Risk: High
CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]
CVE-ID: CVE-2025-21381
CWE-ID:
CWE-822 - Untrusted Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to untrusted pointer dereference in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsOffice Online Server: All versions
Microsoft Office: 2019
Microsoft Excel: 2016
Microsoft Office LTSC: 2021 - 2024 for Mac
Microsoft 365 Apps for Enterprise: 32-bit Systems - 64-bit Systems
CPE2.3- cpe:2.3:a:microsoft:office_online_server:*:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2021:for Mac:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_office_ltsc:2024:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:32-bit_Systems:*:*:*:*:*:*:*
- cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:64-bit_Systems:*:*:*:*:*:*:*
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21381
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
