CVE-2026-50517

NVD: Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.

Source-published summary

NVD: Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.

Possible impact

This critical severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for critical severity review.

Affected context

vendor/product: microsoft / 365_copilot; affected version context: -

Remediation / advisory

Remediation reference present; patch status requires confirmation in the linked advisory.

Why it matters

This critical severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for critical severity review.; CVSS 9.9 (CRITICAL); EPSS percentile 66; not listed in KEV; Remediation reference present; patch status requires confirmation in the linked advisory; sources: NVD, Vendor Advisory.

What to verify

Confirm affected product/version, vendor advisory, patch or mitigation, and exposure.

Exposure hint

exposure unknown

Impact tags

Urgency reasons

Source-derived note

Summary derived from NVD / Vendor Advisory description; unsafe procedural detail is not shown.

Redaction metadata

source summary used

True

fallback summary used

False

unsafe procedural detail present

false

raw source displayed

false

public summary redacted

true

Remediation handoff

Public-safe static handoff for human/Codex remediation planning. Scan, patch, external execution, and auto remediation are disabled.

Safety note

This radar shows source-published defensive context only. Exploit procedures, exploit strings, scanner commands, and auto-remediation are not provided.

Official references

• https://nvd.nist.gov/vuln/detail/CVE-2026-50517
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50517