CVE-2026-21520
Copilot Studio Information Disclosure Vulnerability
Description
Exposure of Sensitive Information to an Unauthorized Actor in Copilot Studio allows a unauthenticated attacker to view sensitive information through network attack vector
INFO
Published Date :
Jan. 22, 2026, 11:15 p.m.
Last Modified :
Feb. 2, 2026, 1:31 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | f38d906d-7342-40ea-92c1-6c4a2c6478c8 | ||||
| CVSS 3.1 | HIGH | [email protected] |
Public PoC/Exploit Available at Github
CVE-2026-21520 has a 3 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-21520.
| URL | Resource |
|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21520 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-21520 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-21520
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
A curated timeline of real AI agent security incidents, breaches, and vulnerabilities (2024-2026). Every entry sourced and dated.
ai-agent-security ai-agents ai-security awesome-list cybersecurity llm-security mcp-security prompt-injection supply-chain-security adversarial-attacks agent-security agentic-ai ai-attacks ai-safety cve incident-response owasp red-team security-research vulnerability
Security research and exploit development: vulnerability analysis, exploit chain implementation, post-exploitation tradecraft, and defensive assessment tooling. Covers browser engines, persistence mechanisms, credential harvesting, C2 patterns, and AI-accelerated attack automation.
ai-security browser-security credential-harvesting cve exploit-development post-exploitation proof-of-concept red-team reverse-engineering security-research streamlit vulnerability-analysis worm
Shell HTML JavaScript Batchfile PowerShell Python Makefile Rust C YARA
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-21520 vulnerability anywhere in the article.
-
The Hacker News
Google Patches Antigravity IDE Flaw Enabling Prompt Injection Code Execution
Cybersecurity researchers have discovered a vulnerability in Google's agentic integrated development environment (IDE), Antigravity, that could be exploited to achieve code execution. The flaw, since ... Read more
-
Help Net Security
Capsule Security debuts with $7 million funding to secure AI agent behavior
Capsule Security has launched from stealth with a $7 million seed round led by Lama Partners and Forgepoint Capital International. It prevents AI agents from being manipulated, misbehaving, or silentl ... Read more
The following table lists the changes that have been made to the
CVE-2026-21520 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 02, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:microsoft:copilot_studio:-:*:*:*:*:*:*:* Added Reference Type Microsoft Corporation: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21520 Types: Vendor Advisory -
New CVE Received by [email protected]
Jan. 22, 2026
Action Type Old Value New Value Added Tag exclusively-hosted-service Added Description Exposure of Sensitive Information to an Unauthorized Actor in Copilot Studio allows a unauthenticated attacker to view sensitive information through network attack vector Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-77 Added Reference https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21520