CVE-2026-43074
Modified Modified - Updated After Analysis
eventpoll Use-After-Free in Linux Kernel

Publication date: 2026-05-06

Last updated on: 2026-06-01

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: eventpoll: defer struct eventpoll free to RCU grace period In certain situations, ep_free() in eventpoll.c will kfree the epi->ep eventpoll struct while it still being used by another concurrent thread. Defer the kfree() to an RCU callback to prevent UAF.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-05-06
Last Modified
2026-06-01
Generated
2026-06-16
AI Q&A
2026-05-07
EPSS Evaluated
2026-06-15
NVD
CVE-2026-43074
EUVD
EUVD-2026-27558
Affected Vendors & Products
Showing 12 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.4
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel From 6.13 (inc) to 6.18.24 (exc)
linux linux_kernel From 6.19 (inc) to 6.19.14 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.83 (exc)
linux linux_kernel From 6.4.1 (inc) to 6.6.136 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-401 The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Mitigation Strategies

To mitigate this vulnerability, update the Linux kernel to a version where the eventpoll use-after-free issue has been fixed by deferring the kfree() call to an RCU callback.

Executive Summary

This vulnerability exists in the Linux kernel's eventpoll subsystem. Specifically, the function ep_free() in eventpoll.c may free (kfree) the eventpoll structure (epi->ep) while it is still being accessed by another concurrent thread. This leads to a use-after-free (UAF) condition. The fix defers the freeing of this structure to an RCU (Read-Copy-Update) grace period callback, ensuring the structure is not freed while still in use.

Impact Analysis

The use-after-free vulnerability can lead to undefined behavior including potential system crashes, data corruption, or exploitation by attackers to execute arbitrary code or escalate privileges. Since the eventpoll structure may be accessed concurrently, freeing it prematurely can destabilize the kernel and compromise system security.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-43074. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart