Exploited vulnerability · CISA KEV
Is CVE-2023-0266 exploited? Yes: in CISA KEV since 30 Mar 2023
Gociux · Linux Kernel · data: CISA KEV, CVE record, FIRST EPSS
Yes. CVE-2023-0266, Linux Kernel Use-After-Free Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 30 Mar 2023, 59 days after it was published. It affects Linux Kernel. If you run it, CISA's required action is: Apply updates per vendor instructions.
exploitedYesCISA KEV · 30 Mar 2023
ransomwareNot knownno confirmed use
EPSSbelow top 10%lower predicted activity right now (it is still confirmed exploited)
severity7.9CVSS 3.1 · high
US federal due20 Apr 2023BOD 22-01 deadline
What it is
Linux kernel contains a use-after-free vulnerability that allows for privilege escalation to gain ring0 access from the system user.
| Vendor | Linux (32 exploited CVEs in KEV) |
| Product | Kernel |
| Vulnerability | Linux Kernel Use-After-Free Vulnerability |
| Weakness | CWE-416 |
| Published | 30 Jan 2023 |
| Added to KEV | 30 Mar 2023 |
| Reported by (CNA) | Google |
What to do
- Check whether you run it. Look for Kernel in your asset inventory, including appliances and cloud images. Stack check lists every exploited Linux CVE at once.
- Apply the fix. Apply updates per vendor instructions.
- If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 30 Jan 2023.
- Get told next time. Email alerts when CISA adds a CVE for Linux.
Other exploited CVEs in Kernel
- CVE-2026-46300: Linux Kernel Missing Initialization of a Variable Vulnerability (28 Oct 2026)
- CVE-2025-39964: Linux Kernel Race Condition Vulnerability (18 Sep 2026)
- CVE-2026-53266: Linux Kernel Out-of-Bounds Write Vulnerability (18 Sep 2026)
- CVE-2025-39682: Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability (18 Sep 2026)
- CVE-2026-53362: Linux Kernel Unspecified Vulnerability (27 Aug 2026)
- CVE-2022-0995: Linux Kernel Out-of-Bounds Write Vulnerability (26 Aug 2026)
References
Questions
Is CVE-2023-0266 being exploited?
Yes. CISA added CVE-2023-0266 to the Known Exploited Vulnerabilities catalog on 30 Mar 2023, which means there is reliable evidence of exploitation in the wild.
Is CVE-2023-0266 used in ransomware attacks?
CISA does not list known ransomware use for it. That can change, and exploitation alone is reason to fix it first.
How do I fix CVE-2023-0266?
Apply updates per vendor instructions. Check Linux's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected Kernel and watch it for signs of compromise.
Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in March 2023 · Linux scorecard · act-now radar.
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