CVE-2023-2236 | Use-after-free in Linux kernel's Performance Events subsystem

Exp

A use-after-free vulnerability in the Linux Kernel io_uring subsystem can be exploited to achieve local privilege escalation. Both io_install_fixed_file and its callers call fput in a file in case of an error, causing a reference underflow which leads to a use-after-free vulnerability. We recommend upgrading past commit 9d94c04c0db024922e886c9fd429659f22f48ea4.

Published: 2023-05-01 Last update: 2025-02-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-2236 is rated Exploit Available (57.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.12%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-2236

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-2236

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-12 0.03% 0.12% +0.10%
2 2025-11-21 0.07% 0.03% -0.04%
3 2025-11-18 — 0.07% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-2236

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2023-2236

OS Trackers for CVE-2023-2236

vendor priority summary link
debian unimportant CVE-2023-2236 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-2236
redhat high — https://access.redhat.com/security/cve/CVE-2023-2236
suse high CVE-2023-2236 severity important: SUSE including 13 source package names (kernel-default, kernel-default-base, …), 195 product×package rows across 47 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 7, … (47 product lines)): Known Not Affected 195. https://www.suse.com/security/cve/CVE-2023-2236/
ubuntu high CVE-2023-2236 high priority: Ubuntu including 122 source packages (linux, linux-allwinner, …), 1183 status rows across 10 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 852, not-affected 144, released 111, ignored 76. https://ubuntu.com/security/CVE-2023-2236

Affected software / configurations for CVE-2023-2236

Vendor Product Version Raw CPE
linux linux_kernel >= 5.19, < 6.0.11 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
netapp hci_baseboard_management_controller h300s cpe:2.3:a:netapp:hci_baseboard_management_controller:h300s:*:*:*:*:*:*:*
netapp hci_baseboard_management_controller h410c cpe:2.3:a:netapp:hci_baseboard_management_controller:h410c:*:*:*:*:*:*:*
netapp hci_baseboard_management_controller h410s cpe:2.3:a:netapp:hci_baseboard_management_controller:h410s:*:*:*:*:*:*:*
netapp hci_baseboard_management_controller h500s cpe:2.3:a:netapp:hci_baseboard_management_controller:h500s:*:*:*:*:*:*:*
netapp hci_baseboard_management_controller h700s cpe:2.3:a:netapp:hci_baseboard_management_controller:h700s:*:*:*:*:*:*:*

References for CVE-2023-2236

cvelogic Threat Intelligence