Review reviewHigh

CVE-2026-58529

Microsoft Windows 11 version 26H1, windows 11 26h1

Out-of-bounds read in Active Directory Federation Services (AD FS) allows an authorized attacker to disclose information over a network.

CVSS
7.1
EPSS
0.95%
57.3% percentile
CISA KEV
Not listed
Published
2026.07.15
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.95%
Technical severityCVSS 7.1

Vulnerability overview

Out-of-bounds read in Active Directory Federation Services (AD FS) allows an authorized attacker to disclose information over a network.

Affected product and versions

Product
Microsoft Windows 11 version 26H1, windows 11 26h1
Affected versions
>= 10.0.28000.0 < 10.0.28000.2525, < 10.0.28000.2525
Fixed versions
10.0.28000.2525

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Microsoft Windows 11 version 26H1, windows 11 26h1 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
CWE
CWE-125