CVE-2025-68198

Kernel crash via wrong crashkernel resource update

Published Dec 16, 2025 · Updated Dec 16, 2025

Denial of service in affected Linux kernel versions allows local users to crash the host via repeated crashkernel reservation shrinks. The __crash_shrink_memory() function in kernel/crash_core.c updates crashk_res when it must update crashk_low_res, leaving an invalid resource after the first shrink. The crash requires a high crashkernel reservation and permission to write /sys/kernel/kexec_crash_size twice below the low reservation, causing a NULL-pointer dereference and service interruption.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in affected Linux kernel versions allows local users to crash the host via repeated crashkernel reservation shrinks. The __crash_shrink_memory() function in kernel/crash_core.c updates crashk_res when it must update crashk_low_res, leaving an invalid resource after the first shrink. The crash requires a high crashkernel reservation and permission to write /sys/kernel/kexec_crash_size twice below the low reservation, causing a NULL-pointer dereference and service interruption.

The record

CVE
CVE-2025-68198
Published
Dec 16, 2025
Updated
Dec 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=16c6006af4d4e70ecef93977a5314409d931020b <00fbff75c5acb4755f06f08bd1071879c63940c5
  2. Affected versionversion=16c6006af4d4e70ecef93977a5314409d931020b <a2bd247f8c6c5ac3f0ba823a2fffd77bb9cdf618
  3. Affected versionversion=16c6006af4d4e70ecef93977a5314409d931020b <f01f9c348d76d40bf104a94449e3ce4057fdefee
  4. Affected versionversion=16c6006af4d4e70ecef93977a5314409d931020b <f89c5e7077f63e45e8ba5a77b7cf0803130367e6
  5. Affected versionversion=6.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=16c6006af4d4e70ecef93977a5314409d931020b <00fbff75c5acb4755f06f08bd1071879c63940c5; version=16c6006af4d4e70ecef93977a5314409d931020b <a2bd247f8c6c5ac3f0ba823a2fffd77bb9cdf618; version=16c6006af4d4e70ecef93977a5314409d931020b <f01f9c348d76d40bf104a94449e3ce4057fdefee; version=16c6006af4d4e70ecef93977a5314409d931020b <f89c5e7077f63e45e8ba5a77b7cf0803130367e6; version=6.5

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/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.

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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

T1499Endpoint Denial of Service

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

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Your stack

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