CVE-2025-38437Network attack vector

Kernel code execution via double reference release

Published Jul 25, 2025 · Updated Aug 5, 2026

Use-after-free in Linux ksmbd allows remote authenticated users to execute kernel code through a crafted SMB2 oplock break acknowledgment. When ksmbd_iov_pin_rsp fails, the error path still reads opinfo->state and releases opinfo and the file reference twice, freeing objects that remain reachable. A valid SMB session, tree connection, and open handle are required; repeated acknowledgments and memory pressure can also trigger a kernel panic.

CVSS severity8.8
High
EPSS probability0.37%
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 ksmbd allows remote authenticated users to execute kernel code through a crafted SMB2 oplock break acknowledgment. When ksmbd_iov_pin_rsp fails, the error path still reads opinfo->state and releases opinfo and the file reference twice, freeing objects that remain reachable. A valid SMB session, tree connection, and open handle are required; repeated acknowledgments and memory pressure can also trigger a kernel panic.

The record

CVE
CVE-2025-38437
Published
Jul 25, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 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=0626e6641f6b467447c81dd7678a69c66f7746cf <50f930db22365738d9387c974416f38a06e8057e
  2. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <8106adc21a2270c16abf69cd74ccd7c79c6e7acd
  3. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <815f1161d6dbc4c54ccf94b7d3fdeab34b4d7477
  4. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <97c355989928a5f60b228ef5266c1be67a46cdf9
  5. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <e38ec88a2b42c494601b1213816d75f0b54d9bf0
  6. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0626e6641f6b467447c81dd7678a69c66f7746cf <50f930db22365738d9387c974416f38a06e8057e; version=0626e6641f6b467447c81dd7678a69c66f7746cf <8106adc21a2270c16abf69cd74ccd7c79c6e7acd; version=0626e6641f6b467447c81dd7678a69c66f7746cf <815f1161d6dbc4c54ccf94b7d3fdeab34b4d7477; version=0626e6641f6b467447c81dd7678a69c66f7746cf <97c355989928a5f60b228ef5266c1be67a46cdf9; version=0626e6641f6b467447c81dd7678a69c66f7746cf <e38ec88a2b42c494601b1213816d75f0b54d9bf0; version=5.15

Published CVSS scores

8.8LinuxCVSS:3.1/AV:N/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation
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