CriticalVulnerabilityLLM-specific

CVE-2026-24307: M365 Copilot improper input validation allows information disclosure

Source: NVD(opens in a new tab)
Identifier: CVE-2026-24307
Published: January 22, 2026
Record updated: October 9, 2026

Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.9%

Summary

CVE-2026-24307 is an improper validation of specified type of input (CWE-1287) in M365 Copilot. According to the source, an unauthorized attacker can exploit it over a network to disclose information. NVD had not yet provided an assessment when the entry was published on 01/22/2026, and last modified 02/12/2026.

Mitigation

The source does not state a fix yet. Check the original advisory for updates.

Details

Scores and exploitation

CVSS score: 9.3(critical)
EPSS: 0.9%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 4, 2026.

Weaknesses and techniques

Weakness (CWE): CWE-1287

Affected

Vendors: Microsoft

Classification

Attack sophistication: Moderate
AI component targeted: API
Impact: Confidentiality
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-24307

First tracked: February 15, 2026 at 08:51 PM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 90% (self-assessed)

Topics

Coding assistants

Summary

Mitigation

Topics

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