CVE-2026-24307: Microsoft 365 Copilot · Improper Validation of Specified Type of Input
Affects Microsoft 365 CopilotSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical · patch available : patch Microsoft 365 Copilot as a priority.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.9% chance of exploitation in 30 days – higher than 59% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 22 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-26.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MicrosoftMicrosoft 365 Copilot | Affected
| Fixed in– |
AI-suggested
Microsoft has released an official fix for this vulnerability in Microsoft 365 Copilot. As this is a cloud service, Microsoft manages the remediation server-side. Users and administrators should ensure their Microsoft 365 Copilot service is updated according to Microsoft's guidance in the official advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-24307. No additional user action is required beyond applying the official fix.
Description
Improper validation of specified type of input in M365 Copilot allows an unauthorized attacker to disclose information over a network.