CVE-2026-42824

CVE Enrichment

CVSS: 7.5 HIGH
EPSS: 7.64%
EPSS Percentile: 94.54%
CISA KEV: Not listed

Description

Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an unauthorized attacker to disclose information over a network.

Technical Details

CVSS Version: 3.1
CNA / NVD Source: [email protected]
Published: 05-Jun-2026 06:17
Last Modified: 23-Jul-2026 14:10
EPSS Date: 2026-10-27
CWE: CWE-77

CVSS Vector


            CVSS:3.1                            AV:N /
                            AC:L /
                            PR:N /
                            UI:N /
                            S:U /
                            C:H /
                            I:N /
                            A:N

CNA Products / Version Status

Microsoft · Microsoft 365 Copilot Source: CNA · [email protected]
Default status: unknown

- — affected

Affected Products / Versions

microsoft / copilot Source: NVD CPE · affected
Version / affected range: -
cpe:2.3:a:microsoft:copilot:-:*:*:*:*:*:*:*

References

[email protected]

Last enrichment sync: 05-Nov-2026 05:46
Sources: NVD · FIRST EPSS · CISA KEV
Latest successful provider update; providers refresh independently.

Reported Context (4)

used Bing’s image search endpoint as an SSRF-powered exfil proxy. Microsoft remediated the issue as CVE-2026-42824, and Varonis says it was a proof-of-concept, not observed exploitation. Weekly Security Roundup: Copilot SearchLeak, AI Security Deals and Surveillance Misuse
Microsoft assigned CVE-2026-42824 and mitigated the issue on the backend, while defenders are advised to monitor suspicious q-parameter payloads and unusual Bing image requests. SearchLeak Flaw Could Expose Microsoft 365 Copilot Data With One Click
Microsoft fixed the flaw as CVE-2026-42824, while researchers showed how prompt injection, an HTML rendering race condition, and a Bing SSRF issue could be chained to exfiltrate emails, calendar details, and documents. SearchLeak Flaw Could Expose Microsoft 365 Copilot Data Through Crafted Links
Microsoft patched the issue as CVE-2026-42824 with critical severity, and the chain could expose emails, security codes, calendar data, SharePoint documents, and OneDrive files with just a single click. SearchLeak Research Details One-Click Data Exfiltration Chain in Microsoft 365 Copilot

CVE (1)

People (1)

MITRE ATT&CK (4)

Vendors (2)

Products (8)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.