How severe is CVE-2018-8440?

CVE-2018-8440 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2018-8440?

Affected package information for CVE-2018-8440 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2018-8440?

No fixed release is recorded for CVE-2018-8440 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2018-8440 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2018-8440 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2018-8440 actively exploited in the wild?

Yes. There are 8 known exploit references for CVE-2018-8440, including 6 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2018-8440?

CVE-2018-8440 has an EPSS (Exploit Prediction Scoring System) score of 18.5%, placing it in the 97th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2018-8440 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2018-8440 (Microsoft Windows Privilege Escalation Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-03-28. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-04-18. The required action was: Apply updates per vendor instructions. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

When was CVE-2018-8440 published, and has it been updated?

CVE-2018-8440 was published on September 13, 2018 and was last updated on October 21, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

CISA KEV · ACTIVELY EXPLOITED

HIGH severity

CVE-2018-8440 — Microsoft

HIGH

CVE-2018-8440 is a high-severity (CVSS 7.8) vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-28) and has been used in ransomware campaigns — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

An elevation of privilege vulnerability exists when Windows improperly handles calls to Advanced Local Procedure Call (ALPC), aka "Windows ALPC Elevation of Privilege Vulnerability."…

Published

Sep 13, 2018

Updated

Oct 21, 2025

Affected

10 products

Patched

See advisory

Exploits

8 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-03-28 — including use in ransomware campaigns. Federal agencies were required to remediate by 2022-04-18.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2018-8440.

EPSS Exploitation Probability

via FIRST.org ↗

18.5%probability of exploitation in next 30 days

Moderate Risk+0.14%

Lower risk than most CVEs97th percentile — riskier than 97% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2018-8440 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.

Description

An elevation of privilege vulnerability exists when Windows improperly handles calls to Advanced Local Procedure Call (ALPC), aka "Windows ALPC Elevation of Privilege Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.

Affected Products

10 products · 12 configurations

windows 7microsoft

all

windows 8.1microsoft

all

windows 10 1607microsoft

all

windows 10 1703microsoft

all

windows 10 1709microsoft

all

windows 10 1803microsoft

all

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.