CVE-2026-21250

Windows HTTP.sys Elevation of Privilege Vulnerability

Untrusted pointer dereference in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.

Affected

Microsoft · Windows 11 Version 24H2 · Windows 11 Version 25H2 · Windows 11 version 26H1 · Windows 11 Version 26H1 · Windows Server 2022, 23H2 Edition (Server Core installation) · Windows Server 2025

CVSS v3.1 MICROSOFT

7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

1.11% chance of exploitation in the next 30 days, 65th percentile

Published

2026-02-10

Updated

2026-08-19

Proof-of-concept exploits (2)

• kaleth4/CVE-2026-212500★ · 2026-05-04
• BlackRainLabs/AI-PoCs0★ · 2026-05-05

ExploitDB entries (1)

• https://www.exploit-db.com/exploits/52546

Security advisories

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21250

References

• CVE Record
• NVD entry

Related

• CVE-2014-6271
• CVE-2019-7711
• CVE-2021-44228
• CVE-2022-30190
• CVE-2024-6387
• CVE-2024-6409