CVE-2025-71155

Guest memory corruption via unchecked swapped PTE clearing

Published Jan 23, 2026 · Updated Jan 23, 2026

Memory corruption in s390 KVM in Linux Kernel 6.17.4 through 6.18.3 allows local users to corrupt guest memory via page zapping. The gmap_helper_zap_one_page() helper cleared a swapped page-table entry without first checking that its PGSTE usage state was unused or zero. Reachability requires an affected s390 KVM host and the specific swapped-entry state; the published impact is guest-memory corruption, not host takeover.

CVSS severity7.8
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in s390 KVM in Linux Kernel 6.17.4 through 6.18.3 allows local users to corrupt guest memory via page zapping. The gmap_helper_zap_one_page() helper cleared a swapped page-table entry without first checking that its PGSTE usage state was unused or zero. Reachability requires an affected s390 KVM host and the specific swapped-entry state; the published impact is guest-memory corruption, not host takeover.

The record

CVE
CVE-2025-71155
Published
Jan 23, 2026
Updated
Jan 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-787
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 2026Record 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=5deafa27d9ae040b75d392f60b12e300b42b4792 <2af2abbcbf8573100288e8f8aea2dab8a2a0ceb7
  2. Affected versionversion=5deafa27d9ae040b75d392f60b12e300b42b4792 <2f393c228cc519ddf19b8c6c05bf15723241aa96
  3. Affected versionversion=6.18
  4. Affected versionversion=919efcadb63fc3d3a82c3de7194140e0b28903dc

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5deafa27d9ae040b75d392f60b12e300b42b4792 <2af2abbcbf8573100288e8f8aea2dab8a2a0ceb7; version=5deafa27d9ae040b75d392f60b12e300b42b4792 <2f393c228cc519ddf19b8c6c05bf15723241aa96; version=6.18; version=919efcadb63fc3d3a82c3de7194140e0b28903dc

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.3Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/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.

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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

CWE-787Out-of-bounds Write

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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