CVE-2026-21521: CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences in Microsoft Microsoft 365 Word Copilot
Improper neutralization of escape, meta, or control sequences in Copilot allows an unauthorized attacker to disclose information over a network.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-21521) in Microsoft 365 Word Copilot is categorized under CWE-150, indicating improper neutralization of escape, meta, or control sequences. Exploitation can lead to unauthorized information disclosure over a network. The CVSS 3.1 vector indicates network attack vector, low attack complexity, no privileges required, but user interaction is needed, with a scope change and high impact on confidentiality. The vulnerability is published and a patch is available.
Potential Impact
An attacker can exploit this vulnerability to disclose sensitive information over a network without needing privileges, potentially compromising confidentiality. There is no impact on integrity or availability. No known exploits are reported in the wild at this time.
Mitigation Recommendations
A patch is available for this vulnerability and should be applied promptly to mitigate the risk. Since this is not a cloud service, organizations must update their Microsoft 365 Word Copilot installations accordingly. No additional vendor advisory details are provided, so check official Microsoft channels for the patch and deployment instructions.
CVE-2026-21521: CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences in Microsoft Microsoft 365 Word Copilot
Description
Improper neutralization of escape, meta, or control sequences in Copilot allows an unauthorized attacker to disclose information over a network.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-21521) in Microsoft 365 Word Copilot is categorized under CWE-150, indicating improper neutralization of escape, meta, or control sequences. Exploitation can lead to unauthorized information disclosure over a network. The CVSS 3.1 vector indicates network attack vector, low attack complexity, no privileges required, but user interaction is needed, with a scope change and high impact on confidentiality. The vulnerability is published and a patch is available.
Potential Impact
An attacker can exploit this vulnerability to disclose sensitive information over a network without needing privileges, potentially compromising confidentiality. There is no impact on integrity or availability. No known exploits are reported in the wild at this time.
Mitigation Recommendations
A patch is available for this vulnerability and should be applied promptly to mitigate the risk. Since this is not a cloud service, organizations must update their Microsoft 365 Word Copilot installations accordingly. No additional vendor advisory details are provided, so check official Microsoft channels for the patch and deployment instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-30T18:10:54.846Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6972ad5b4623b1157c962ba3
Added to database: 1/22/2026, 11:06:03 PM
Last enriched: 4/3/2026, 12:54:38 PM
Last updated: 5/10/2026, 4:49:04 AM
Views: 163
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