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CVE record · CVE-2026-21530

Windows Rich Text Edit Elevation of Privilege Vulnerability

CVSS 6.7 MediumEPSS 0.0032 · 25th percentile

Published by the CVE Program (CNA: microsoft) at 12 May 2026, 16:58 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
VendorProductVersions
Microsoft Microsoft 365 Apps for Enterprise
  • affected 16.0.1 to before https://aka.ms/OfficeSecurityReleases custom
Microsoft Microsoft Office 2016
  • affected 16.0.0 to before 16.0.5556.1000 custom
Microsoft Microsoft Office 2019
  • affected 19.0.0 to before https://aka.ms/OfficeSecurityReleases custom
Microsoft Microsoft Office LTSC 2021
  • affected 16.0.1 to before https://aka.ms/OfficeSecurityReleases custom
Microsoft Microsoft Office LTSC 2024
  • affected 16.0.0 to before https://aka.ms/OfficeSecurityReleases custom
Microsoft Windows 10 Version 1607
  • affected 10.0.14393.0 to before 10.0.14393.9140 custom
Microsoft Windows 10 Version 1809
  • affected 10.0.17763.0 to before 10.0.17763.8755 custom
Microsoft Windows 10 Version 21H2
  • affected 10.0.19044.0 to before 10.0.19044.7291 custom
Microsoft Windows 10 Version 22H2
  • affected 10.0.19045.0 to before 10.0.19045.7417 custom
Microsoft Windows 11 version 23H2
  • affected 10.0.22631.0 to before 10.0.22631.7079 custom
Microsoft Windows 11 Version 23H2
  • affected 10.0.22631.0 to before 10.0.22631.7219 custom
Microsoft Windows 11 Version 24H2
  • affected 10.0.26100.0 to before 10.0.26100.8457 custom
Microsoft Windows 11 Version 25H2
  • affected 10.0.26200.0 to before 10.0.26200.8457 custom
Microsoft Windows 11 version 26H1
  • affected 10.0.28000.0 to before 10.0.28000.2113 custom
Microsoft Windows Server 2012
  • affected 6.2.9200.0 to before 6.2.9200.26079 custom
Microsoft Windows Server 2012 (Server Core installation)
  • affected 6.2.9200.0 to before 6.2.9200.26079 custom
Microsoft Windows Server 2012 R2
  • affected 6.3.9600.0 to before 6.3.9600.23181 custom
Microsoft Windows Server 2012 R2 (Server Core installation)
  • affected 6.3.9600.0 to before 6.3.9600.23181 custom
Microsoft Windows Server 2016
  • affected 10.0.14393.0 to before 10.0.14393.9140 custom
Microsoft Windows Server 2016 (Server Core installation)
  • affected 10.0.14393.0 to before 10.0.14393.9140 custom
Microsoft Windows Server 2019
  • affected 10.0.17763.0 to before 10.0.17763.8755 custom
Microsoft Windows Server 2019 (Server Core installation)
  • affected 10.0.17763.0 to before 10.0.17763.8755 custom
Microsoft Windows Server 2022
  • affected 10.0.20348.0 to before 10.0.20348.5139 custom
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation)
  • affected 10.0.25398.0 to before 10.0.25398.2330 custom
Microsoft Windows Server 2025
  • affected 10.0.26100.0 to before 10.0.26100.32860 custom
Microsoft Windows Server 2025 (Server Core installation)
  • affected 10.0.26100.0 to before 10.0.26100.32860 custom
Identifiers
CVE-2026-21530
CNA
microsoft
Weakness (CWE)
CWE-415
Tags
Published
12 May 2026
Updated
10 Aug 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

ScoreRatingCVSSVectorSource
6.7 Medium 3.1 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C CNA (microsoft)
  • CISA KEV Not listed.
  • EPSS 0.0032, the 25th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 12 May 2026. New records show when each source confirmed them.

Sources

References from the CNA

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.