CVE-2026-23234

What it is

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid UAF in f2fs_write_end_io() As syzbot reported an use-after-free issue in f2fs_write_end_io(). It is caused by below race condition: loop device umount - worker_thread - loop_process_work - do_req_filebacked - lo_rw_aio - lo_rw_aio_complete - blk_mq_end_request - blk_update_request - f2fs_write_end_io - dec_page_count - folio_end_writeback - kill_f2fs_super - kill_block_super - f2fs_put_super : free(sbi) : get_pages(, F2FS_WB_CP_DATA) accessed sbi which is freed In kill_f2fs_super(), we will drop all page caches of f2fs inodes before call free(sbi), it guarantee that all folios should end its writeback, so it should be safe to access sbi before last folio_end_writeback(). Let's relocate ckpt thread wakeup flow before folio_end_writeback() to resolve this issue.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-03-04 15:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:21 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 7.8 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-03-04 15:16 UTC

Last modified

2026-06-17 10:21 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-416 · Use after free

Record status

Analyzed

Affected

• Linux Kernel < 5.10.251
• Linux Kernel < 5.15.201
• Linux Kernel < 6.1.164
• Linux Kernel < 6.6.127
• Linux Kernel < 6.12.74
• Linux Kernel < 6.18.13
• Linux Kernel < 6.19.3

Attack profile CVSS 3.1 · 7.8

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-23234.md and follow it. Check whether this project is affected by CVE-2026-23234. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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