CVE-2026-81391 json
Microsoft Excel Information Disclosure Vulnerability
published 2026-09-08 2 mo ago modified 2026-10-31 9 d ago also EUVD-2026-73860
- cvss
- 5.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 45%
- public exploits
- 0
- none known
Summary
Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
Patch / fix
- Microsoft Microsoft 365 Apps for Enterprise 16.0.20326.20138
- Microsoft Microsoft Excel 2016 16.0.5569.1003
- Microsoft Microsoft Office 2016 16.0.5569.1003
- Microsoft Microsoft Office 2019 16.0.10417.20207
- Microsoft Microsoft Office 365 for Mac 16.113.26091433
- Microsoft Microsoft Office LTSC 2021 16.0.14334.20906
- Microsoft Microsoft Office LTSC 2024 16.0.17932.20976
- Microsoft Microsoft Office LTSC for Mac 2021 16.113.26091433
- Microsoft Microsoft Office LTSC for Mac 2024 16.113.26091433
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C |
| CNA | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
Affected products
- Microsoft Microsoft 365 Apps for Enterprise
- Microsoft Microsoft Excel 2016
- Microsoft Microsoft Office 2016
- Microsoft Microsoft Office 2019
- Microsoft Microsoft Office 365 for Mac
- Microsoft Microsoft Office LTSC 2021
- Microsoft Microsoft Office LTSC 2024
- Microsoft Microsoft Office LTSC for Mac 2021
- Microsoft Microsoft Office LTSC for Mac 2024
Classification
- Weakness
-
- CWE-908 Use of Uninitialized Resource
References
-
msrc.microsoft.com
/update-guide/vulnerability/CVE-2026-81391
vendor-advisory, patch
Sources
- CVE List CVE-2026-81391
- NVD CVE-2026-81391
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.