CVE-2025-40364

Local privilege escalation via stale buffer-list pointer

Published Apr 18, 2025 · Updated Aug 5, 2026

Use-after-free in Linux kernel io_uring allows local users to escalate privileges through a stale provided-buffer-list pointer. The io_req_prep_async() path retains req->buf_list after the buffer ring is unregistered, so slab reallocation turns later cleanup and buffer commits into user-influenced reads and writes. Local users need no capabilities or victim action; successful heap grooming grants kernel-level privilege escalation, while failed attempts can panic the kernel.

CVSS severity7.8
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in Linux kernel io_uring allows local users to escalate privileges through a stale provided-buffer-list pointer. The io_req_prep_async() path retains req->buf_list after the buffer ring is unregistered, so slab reallocation turns later cleanup and buffer commits into user-influenced reads and writes. Local users need no capabilities or victim action; successful heap grooming grants kernel-level privilege escalation, while failed attempts can panic the kernel.

The record

CVE
CVE-2025-40364
Published
Apr 18, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.19
  2. Affected versionversion=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <233b210a678bddf8b49b02a070074a52b87e6d43
  3. Affected versionversion=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <35ae7910c349fb3c60439992e2e0e79061e95382
  4. Affected versionversion=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <a1b17713b32c75a90132ea2f92b1257f3bbc20f3
  5. Affected versionversion=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <a94592ec30ff67dc36c424327f1e0a9ceeeb9bd3
  6. Affected versionversion=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <b86f1d51731e621e83305dc9564ae14c9ef752bf
  7. Affected versionversion=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <d63b0e8a628e62ca85a0f7915230186bb92f8bb4
  8. Affected versionversion=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <f0ef94553868d07c1b14d7743a7e2553e5a831a3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.19; version=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <233b210a678bddf8b49b02a070074a52b87e6d43; version=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <35ae7910c349fb3c60439992e2e0e79061e95382; version=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <a1b17713b32c75a90132ea2f92b1257f3bbc20f3; version=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <a94592ec30ff67dc36c424327f1e0a9ceeeb9bd3; version=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <b86f1d51731e621e83305dc9564ae14c9ef752bf; version=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <d63b0e8a628e62ca85a0f7915230186bb92f8bb4; version=c7fb19428d67dd0a2a78a4f237af01d39c78dc5a <f0ef94553868d07c1b14d7743a7e2553e5a831a3

Published CVSS scores

7.8LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo