CVE-2026-62818: Windows Active Directory Certificate Services (AD CS) Remote Code Execution Vulnerability

highCVSS 8.8CVE-2026-62818

Use after free in Active Directory Certificate Services (AD CS) allows an authorized attacker to execute code over a network.

CSIRTS triage

vendor: Microsoft product: Windows Active Directory Certificate Services (AD CS)Remote code execution

What: Use-after-free in Active Directory Certificate Services allows remote code execution by authorized attackers.
Who is affected: Authorized attackers with network access to systems running AD CS.
Urgency: Critical (CVSS 8.8) for certificate infrastructure environments; prioritize patching AD CS servers.
Action: Apply Windows security update addressing CVE-2026-62818 and audit AD CS access controls.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch Windows Active Directory Certificate Services (AD CS)

Get an email when a new Windows Active Directory Certificate Services (AD CS) advisory drops — max one per day, one-click unsubscribe.

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 8.8
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62818

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-628180.95% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 58% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-62818	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

critical[NEW] [critical] Microsoft Windows Products: Multiple vulnerabilitiescert-bund
unknownexploitedNCSC-2026-0284 [1.00] [M/H] Vulnerabilities patched in Microsoft Windowsncsc-nl
highCVE-2026-62818: Use after free in Active Directory Certificate Services (AD CS) allows an authorized attacker …nvd

Recent advisories for Windows Active Directory

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

mediumCVE-2026-65777: Inadequate encryption strength in Windows Active Directory allows an authorized attacker to by…nvd · 2026-08-11
highCVE-2026-49179: Improper neutralization of special elements used in a command ('command injection') in Windows…nvd · 2026-08-11
highCVE-2026-49179: Windows Active Directory Domain Services Remote Code Execution Vulnerabilitymsrc · 2026-08-11
highCVE-2026-54115: Integer overflow or wraparound in Windows Active Directory allows an authorized attacker to el…nvd · 2026-07-14
highCVE-2026-50682: Out-of-bounds read in Windows Active Directory allows an authorized attacker to deny service o…nvd · 2026-07-14
highCVE-2026-55001: Improper certificate validation in Windows Active Directory allows an authorized attacker to e…nvd · 2026-07-14