CVE-2023-0266: in the CISA KEV catalogue
Linux Kernel Use-After-Free Vulnerability. CISA added CVE-2023-0266 to the Known Exploited Vulnerabilities catalogue on 2023-03-30 with a default due date of 2023-04-20. Known ransomware campaign use: Unknown. Forensic triage flag: No.
Linux kernel contains a use-after-free vulnerability that allows for privilege escalation to gain ring0 access from the system user. (CISA description)
- Vendor / product
- Linux Kernel
- CWE
- CWE-416
- CISA required action
- Apply updates per vendor instructions.
- EPSS
- 3.7%, percentile 89 (scored 2026-11-03)
EPSS puts about 3.7 in 100 odds (3.7%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 89% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.
Vendor and reference links (from CISA)
Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.
Frequently asked questions
Is CVE-2023-0266 in the CISA KEV catalogue?
Yes. CISA added CVE-2023-0266 (Linux Kernel Use-After-Free Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2023-03-30. CISA's default due date for it is 2023-04-20.
Is CVE-2023-0266 used in ransomware attacks?
CISA marks known ransomware campaign use as Unknown for CVE-2023-0266. That means CISA lacks confirmation, not that ransomware groups do not use it.
What should I do about CVE-2023-0266?
CISA's required action: Apply updates per vendor instructions.
Sources
- CISA, Known Exploited Vulnerabilities Catalog (accessed 2026-11-03)
- FIRST, Exploit Prediction Scoring System (EPSS) (EPSS by FIRST; scores generated by Empirical Security)
- NVD record for CVE-2023-0266