CVE-2025-37949

Guest kernel crash via xenbus request lifetime race

Published May 20, 2025 · Updated Aug 5, 2026

A NULL pointer dereference in Linux xenbus allows local users with privileged Xen guest access to crash the guest kernel. A wake-up can reschedule execution after xs_wait_for_reply frees a request, leaving xenbus_thread to invoke the released request callback. Exploitation requires privileged access inside a Xen guest and interrupts that guest through a kernel fault; no remote vector or privilege escalation is reported.

CVSS severity7.8
High
EPSS probability0.20%
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

A NULL pointer dereference in Linux xenbus allows local users with privileged Xen guest access to crash the guest kernel. A wake-up can reschedule execution after xs_wait_for_reply frees a request, leaving xenbus_thread to invoke the released request callback. Exploitation requires privileged access inside a Xen guest and interrupts that guest through a kernel fault; no remote vector or privilege escalation is reported.

The record

CVE
CVE-2025-37949
Published
May 20, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 20, 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=4.11
  2. Affected versionversion=fd8aa9095a95c02dcc35540a263267c29b8fda9d <0e94a246bb6d9538010b6c02d2b1d4717a97b2e5
  3. Affected versionversion=fd8aa9095a95c02dcc35540a263267c29b8fda9d <1f0304dfd9d217c2f8b04a9ef4b3258a66eedd27
  4. Affected versionversion=fd8aa9095a95c02dcc35540a263267c29b8fda9d <2466b0f66795c3c426cacc8998499f38031dbb59
  5. Affected versionversion=fd8aa9095a95c02dcc35540a263267c29b8fda9d <4d260a5558df4650eb87bc41b2c9ac2d6b2ba447
  6. Affected versionversion=fd8aa9095a95c02dcc35540a263267c29b8fda9d <8b02f85e84dc6f7c150cef40ddb69af5a25659e5
  7. Affected versionversion=fd8aa9095a95c02dcc35540a263267c29b8fda9d <8e9c8a0393b5f85f1820c565ab8105660f4e8f92
  8. Affected versionversion=fd8aa9095a95c02dcc35540a263267c29b8fda9d <cbfaf46b88a4c01b64c4186cdccd766c19ae644c
  9. Affected versionversion=fd8aa9095a95c02dcc35540a263267c29b8fda9d <f1bcac367bc95631afbb918348f30dec887d0e1b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=4.11; version=fd8aa9095a95c02dcc35540a263267c29b8fda9d <0e94a246bb6d9538010b6c02d2b1d4717a97b2e5; version=fd8aa9095a95c02dcc35540a263267c29b8fda9d <1f0304dfd9d217c2f8b04a9ef4b3258a66eedd27; version=fd8aa9095a95c02dcc35540a263267c29b8fda9d <2466b0f66795c3c426cacc8998499f38031dbb59; version=fd8aa9095a95c02dcc35540a263267c29b8fda9d <4d260a5558df4650eb87bc41b2c9ac2d6b2ba447; version=fd8aa9095a95c02dcc35540a263267c29b8fda9d <8b02f85e84dc6f7c150cef40ddb69af5a25659e5; version=fd8aa9095a95c02dcc35540a263267c29b8fda9d <8e9c8a0393b5f85f1820c565ab8105660f4e8f92; version=fd8aa9095a95c02dcc35540a263267c29b8fda9d <cbfaf46b88a4c01b64c4186cdccd766c19ae644c; version=fd8aa9095a95c02dcc35540a263267c29b8fda9d <f1bcac367bc95631afbb918348f30dec887d0e1b

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.1Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.1Red HatCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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