CVE-2026-43074
eventpoll Use-After-Free in Linux Kernel
Publication date: 2026-05-06
Last updated on: 2026-05-20
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| 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 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 Powered Q&A
Can you explain this vulnerability to me?
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.
How can this vulnerability impact me? :
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.
What immediate steps should I take to mitigate this vulnerability?
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.