Threats / Linux / CVE-2023-0266
CVE-2023-0266
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Linux Kernel vulnerability
Linux kernel use-after-free vulnerability enabling privilege escalation from system user to ring0 access.
Verdict
Today item — known-exploited.
A use-after-free flaw in the Linux kernel permits local privilege escalation, allowing an unprivileged system user to gain kernel-level (ring0) access. The vulnerability has been observed in active exploitation.
CISA KEV Yes · 2023-03-305EPSS 0.03702 (verify live)6CVSS 7.93CISA SSVC Exploitation: active · Automatable: no · Impact: total4
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
7 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 2023-03-30).
Probability (EPSS)
EPSS 0.03702 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.9 (CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:H) · Affected: Linux, Kernel. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-416 Use After Free — weakness family: Memory safety.CWE — CNA-assigned (CVE.org); 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 59 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 execute code as an unprivileged system user on a vulnerable Linux system.
Business
An attacker gains a foothold with standard user privileges on the target system.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I trigger the use-after-free condition in the kernel memory management to corrupt kernel state.
Business
Memory safety controls are bypassed, creating conditions for arbitrary code execution.
3
Lateral reach — past segmentation narrative 3
Attacker
I escalate my privileges to ring0 kernel level through the corrupted kernel state.
Business
The attacker achieves complete system compromise with kernel-level access and control.
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