Threadlinqs IntelligenceStart free

VulnerabilityCVE-2026-80098Published 2026-09-03

CVE-2026-80098 — Microsoft Copilot Studio

critical

As of 2026-10-08, CVE-2026-80098 is a CRITICAL-severity vulnerability in Microsoft Copilot Studio, CVSS v3.1 9.3, EPSS 0.4% (40.1th percentile). Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-80098, most recently “September 2026 Microsoft Patch Tuesday — Record 966+ Vulnerabilities with Two Actively Exploited Zero-Days (CVE-2026-81963, CVE-2026-85880) and Multiple Critical Wormable RCEs”.

CVSS v3.1
9.3/10Critical
EPSS
0.4%Higher than 40.1% of scored CVEs
CISA KEV
NoNot in the KEV catalog
Tracked threats
2Campaigns referencing it
Priority
6.3/10Threadlinqs triage score
Published
Updated 2026-10-08
CVSS v3.1 9.3 (CRITICAL) · EPSS 0.4% (higher than 40.1% of all scored CVEs) · Priority 6.3/10 · Published 2026-09-03

Last updated:

What is CVE-2026-80098?

Improper verification of cryptographic signature in Copilot Studio allows an unauthorized attacker to elevate privileges over a network.

The record classifies CVE-2026-80098 under weakness class CWE-347. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 49 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.3 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N/E:U/RL:O/RC:C
EPSS (FIRST)
0.4% probability of exploitation in the next 30 days, higher than 40.1% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
6.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-09-03, last modified 2026-10-08

Is CVE-2026-80098 being exploited?

It currently carries a trending score of 41 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-80098

No vendor patch reference has been recorded for CVE-2026-80098 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-80098

2 tracked threats in the Threadlinqs corpus reference CVE-2026-80098, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on .

Vendor advisory and patch