CVE-2026-26129
High
Published: 07 May 2026
Published
07 May 2026
Modified
08 May 2026
KEV Added
—
Patch
—
CVSS Score
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score
0.0007
22.0th percentile
Risk Priority
15
60% EPSS · 20% KEV · 20% CVSS
Summary
CVE-2026-26129 is a high-severity Improper Neutralization of Special Elements (CWE-138) vulnerability in Microsoft 365 Copilot Chat. Its CVSS base score is 7.5 (High).
Operationally, ranked at the 22.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as Enterprise AI Assistants.
NVD Description
Improper neutralization of special elements in M365 Copilot allows an unauthorized attacker to disclose information over a network.
Deeper analysisAI
Automated synthesis unavailable for this CVE.
Details
- CWE(s)
Affected Products
microsoft
365 copilot chat
all versions
AI Security AnalysisAI
- AI Category
- Enterprise AI Assistants
- Risk Domain
- N/A
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: copilot
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