CVE-2026-100208: Microsoft 365 Apps for Enterprise · Integer Overflow or Wraparound
Affects Microsoft 365 Apps for EnterpriseSource CVE Database V5
Not known to be exploited · CVSS 7.5 High · patch available : patch Microsoft 365 Apps for Enterprise soon.
Data as of 9 Nov 2026, 23:24 UTC
Thin evidence
One scorer or none| CNA (microsoft) | CVSS 3.1 | 7.5 |
|---|
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MicrosoftMicrosoft 365 Apps for Enterprise | Affected
| Fixed in– |
| MicrosoftMicrosoft Office LTSC 2021 | Affected
| Fixed in– |
| MicrosoftMicrosoft Office LTSC 2024 | Affected
| Fixed in– |
AI-suggested
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users and administrators should apply the official update as provided by Microsoft via the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-100208 to ensure protection against this vulnerability.
Description
CVE-2026-100208 is an integer overflow or wraparound vulnerability in Microsoft Office Outlook within Microsoft 365 Apps for Enterprise. This flaw allows an unauthorized attacker to execute code remotely over a network. The vulnerability affects versions 16.0.0 and 16.0.1 of the software. An official fix is available from Microsoft, and the vendor manages remediation for this cloud-hosted service. There are no known exploits in the wild at this time.