What is CVE-2026-26133?
AI command injection in M365 Copilot allows an unauthorized attacker to disclose information over a network.
The record classifies CVE-2026-26133 under weakness class CWE-77. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality. 12 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 244 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.1 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N/E:U/RL:O/RC:C - EPSS (FIRST)
- 0.5% probability of exploitation in the next 30 days, higher than 43.7% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 5.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-03-13
Is CVE-2026-26133 being exploited?
It currently carries a trending score of 16 in the Threadlinqs vulnerability feed.
Affected products and versions
- Microsoft: 365 Copilot for Android, 365 Copilot for iOS, Edge for Android, Edge for iOS, Excel for Android, Excel for iOS, Loop for iOS, OneNote, OneNote for Android, Outlook for Android, Outlook for iOS, Outlook for Mac
How to fix CVE-2026-26133
Patch reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26133. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-26133
1 tracked threat in the Threadlinqs corpus references CVE-2026-26133, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS.