Threats / Microsoft / CVE-2016-7255
CVE-2016-7255
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-09-19
Microsoft Win32k vulnerability
Microsoft Win32k kernel-mode driver improperly handles memory objects, enabling privilege escalation and kernel-mode code execution.
Verdict
Today item, not a backlog item.
A memory handling flaw in Win32k allows local attackers to escalate privileges and execute arbitrary code with kernel privileges. The high EPSS score and active exploitation in the wild indicate significant real-world risk.
CISA KEV Yes · 2021-11-034Ransomware use Flagged4EPSS 0.80968 (verify live)5Exploit Public PoC6CVSS 7.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
14 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.80968 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.8 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) · Affected: Microsoft, Win32k. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-264 Permissions/Privileges/Access Control — weakness family: Authorization / access control.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 1819 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I gain initial access to a target system as a standard user or through a compromised application.
Business
An attacker establishes a foothold on the network with limited privileges, creating an entry point for further compromise.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I craft a malicious input or trigger a specific sequence of operations that causes Win32k to mishandle a kernel object in memory.
Business
The vulnerability becomes the pivot point for converting user-level access into system-level control.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute code that exploits the memory handling flaw to escalate my privileges to kernel mode.
Business
The attacker gains unrestricted control over the operating system, bypassing all security boundaries and access controls.
4
Data at risk — exfiltration narrative 4
Attacker
I run arbitrary code with kernel privileges, allowing me to install rootkits, disable security software, or move laterally across the network.
Business
Complete system compromise enables data theft, malware persistence, lateral movement, and potential compromise of connected infrastructure.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by microsoftCNA
Credited with finding itNo finder is named in the public CVE record or the scanned vendor advisory — attribution scoped to the sources checked.
Found an error? Propose a correction.
A correction is a cited counter-claim — it must cite a source,
gets reviewed by a second human, and is never auto-applied. See the
correction convention and our identity
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