CVE-2026-21520

highpriority · track · 1EPSS 0.015 · 75 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
1.53% (75th) EPSS
CVSS 7.5 · high
Is it mine?
5 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

Exposure of Sensitive Information to an Unauthorized Actor in Copilot Studio allows a unauthenticated attacker to view sensitive information through network attack vector

01

cvss

Technical severity, 0–10. One row per scoring source.

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · FSTEC (BDU) RU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C/CR:H/IR:L/AR:Lsecondary · ENISA EU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · secure@microsoft.com USexploitability 3.9 · impact 3.6
v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C/CR:H/IR:L/AR:Lsecondary · Microsoft Security Response Center US
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-77USCWE-77USCWE-77US
04

affected products (5)

Products and version ranges known to be affected.

05

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-0228Microsoft Copilot Studio: Schwachstelle ermöglicht Offenlegung von InformationenDeutsch2026-01-27csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Microsoft 365 Copilot Studio ausnutzen, um Informationen offenzulegen.

  • msrc_CVE-2026-21520Copilot Studio Information Disclosure Vulnerability2026-01-22csaf · msrc_csafUS

    To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundmsrc_csafnvdNVDCVE.orgMITRE
published 2026-01-22modified 2026-06-17
08

references (3)

External citations — patches, advisories, analysis.

scry

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