CVE-2023-39191Public exploit

Kernel code execution via dynptr type confusion

Published Oct 4, 2023 · Updated Nov 6, 2025

Improper input validation in the Linux kernel eBPF subsystem allows local users with CAP_BPF to execute code in kernel context. The verifier mishandles overlapping dynamic-pointer stack slots, allowing crafted eBPF programs to corrupt dynptr size metadata and gain out-of-bounds read and write access. Exploitation requires CAP_BPF and can escalate that privileged local context to full kernel control, affecting confidentiality, integrity, and availability.

CVSS severity8.2
High
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in the Linux kernel eBPF subsystem allows local users with CAP_BPF to execute code in kernel context. The verifier mishandles overlapping dynamic-pointer stack slots, allowing crafted eBPF programs to corrupt dynptr size metadata and gain out-of-bounds read and write access. Exploitation requires CAP_BPF and can escalate that privileged local context to full kernel control, affecting confidentiality, integrity, and availability.

The record

CVE
CVE-2023-39191
Published
Oct 4, 2023
Updated
Nov 6, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 9.2 Extended Update Support
Classifications
CWE-20, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Red Hat · Red Hat Enterprise Linux 9.2 Extended Update SupportAffected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.

Published CVSS scores

8.2Red HatCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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