CVE-2016-0099: Microsoft Windows Secondary Logon Service Privilege Escalation Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 3 Mar 2022, 2,185 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 37%
EPSS score, percentile 98.5 of all scored records
- How severe?
- 7.8 High
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline 24 Mar 2022. Apply updates per vendor instructions.
- Which versions are affected?
Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: 24 March 2022.
Advisories and patches
Linked from CISA's catalog entry
Affected products and versions
The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
A privilege escalation vulnerability exists in Microsoft Windows if the Windows Secondary Logon Service fails to properly manage request handles in memory. An attacker who successfully exploited this vulnerability could run arbitrary code as an administrator.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2016-0099 to its Known Exploited Vulnerabilities (KEV) catalog on 3 Mar 2022.
- CISA marks it as known to be used in ransomware campaigns.
- The due date CISA sets for the required action is 24 Mar 2022.
- The CVE record was published on 9 Mar 2016, 2,185 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 7.8 (High), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 37% (percentile 98.5), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
The Secondary Logon Service in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 does not properly process request handles, which allows local users to gain privileges via a crafted application, aka "Secondary Logon Elevation of Privilege Vulnerability."
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 9 Mar 2016 | CVE record published |
| 3 Mar 2022 | Added to CISA KEV |
| 24 Mar 2022 | CISA due date for the required action |
| 21 Oct 2025 | CVE record last updated |
References
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