CVE-2026-74631

Kernel memory corruption via SMC splice refcount imbalance

Published Aug 22, 2026 · Updated Aug 25, 2026

Use-after-free in the SMC receive splice path in affected Linux kernel branches allows attackers to corrupt kernel memory via splice(). The smc_rx_splice() function gives candidate pages to splice_to_pipe() before taking per-entry page and socket references, so release callbacks can underflow page refcounts and leave freed pages reachable. Exploitation requires an SMC peer to supply receive data to an application already using splice; the result ranges from kernel disclosure or writes to a kernel panic.

CVSS severity8.4
High
EPSS probability0.14%
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 the SMC receive splice path in affected Linux kernel branches allows attackers to corrupt kernel memory via splice(). The smc_rx_splice() function gives candidate pages to splice_to_pipe() before taking per-entry page and socket references, so release callbacks can underflow page refcounts and leave freed pages reachable. Exploitation requires an SMC peer to supply receive data to an application already using splice; the result ranges from kernel disclosure or writes to a kernel panic.

The record

CVE
CVE-2026-74631
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-911, CWE-416, T1068
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=4.18
  2. Affected versionversion=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <07ad246529d136d5ef441d5ab4c305d132ff3090
  3. Affected versionversion=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <0b7d54cedea5cb158e21925ae0c6c2f5c87ed2a0
  4. Affected versionversion=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <4515c78f4d9fd577270f012efeb062ea58b3682d
  5. Affected versionversion=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <5d9686af2976741bbd79b150d1c9e60b81e7f12e
  6. Affected versionversion=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <7ddc7af2ae7fc5a0c0635b245c0824c8b76de5cb
  7. Affected versionversion=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <af02c67ce654356c58db20a0bb2db33ace3b07a8
  8. Affected versionversion=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <c841789e456ec6751342fa800639ce8e82ff0e6b
  9. Affected versionversion=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <ca8342b5fc24c249fdb998468f6a168b457c67e5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.18; version=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <07ad246529d136d5ef441d5ab4c305d132ff3090; version=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <0b7d54cedea5cb158e21925ae0c6c2f5c87ed2a0; version=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <4515c78f4d9fd577270f012efeb062ea58b3682d; version=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <5d9686af2976741bbd79b150d1c9e60b81e7f12e; version=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <7ddc7af2ae7fc5a0c0635b245c0824c8b76de5cb; version=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <af02c67ce654356c58db20a0bb2db33ace3b07a8; version=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <c841789e456ec6751342fa800639ce8e82ff0e6b; version=9014db202cb764b8e14c53e7bacc81f9a1a2ba7f <ca8342b5fc24c249fdb998468f6a168b457c67e5

Published CVSS scores

8.4Linux CNACVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.4Red HatCVSS:3.1/AV:L/AC:H/PR:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-911Improper Update of Reference Count
CWE-416Use After Free
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