CVE-2023-3640

Name: CVE-2023-3640
Creator: NVD / NIST
Published: 2023-07-24T16:15:13.063+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.70%

Last modified Jun 26, 2026

CVE-2023-3640 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. A possible unauthorized memory access flaw was found in the Linux kernel's cpu_entry_area mapping of X86 CPU data to memory, where a user may guess the location of exception stacks or other important data. Based on the previous CVE-2023-0597, the 'Randomize per-cpu entry area' feature was implemented in /arch/x86/mm/cpu_entry_area.c, which works through the init_cea_offsets() function when KASLR is enabled. EPSS estimates a 0.70% chance of exploitation in the next 30 days.

Description

A possible unauthorized memory access flaw was found in the Linux kernel's cpu_entry_area mapping of X86 CPU data to memory, where a user may guess the location of exception stacks or other important data. Based on the previous CVE-2023-0597, the 'Randomize per-cpu entry area' feature was implemented in /arch/x86/mm/cpu_entry_area.c, which works through the init_cea_offsets() function when KASLR is enabled. However, despite this feature, there is still a risk of per-cpu entry area leaks. This issue could allow a local user to gain access to some important data with memory in an expected location and potentially escalate their privileges on the system.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.70%

48.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	All versions
Redhat	Enterprise Linux	8.0
Redhat	Enterprise Linux	9.0

References

https://access.redhat.com/errata/RHSA-2023:6583
https://access.redhat.com/security/cve/CVE-2023-3640Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2217523Issue Tracking, Third Party Advisory
https://access.redhat.com/security/cve/CVE-2023-3640Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2217523Issue Tracking, Third Party Advisory

Timeline

Published: Jul 24, 2023
Last Modified: Jun 26, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-3640?

How severe is CVE-2023-3640?

CVE-2023-3640 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.70% probability of exploitation in the next 30 days.

How do I fix CVE-2023-3640?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-3640?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST