VulnerabilityPublished 15 Aug 2026Updated 27 Oct 2026

CVE-2026-72292: Linux kernel · KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 7.0.0-1014.14~24.04.1 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 05:11 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 7.0.0-1014.14~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +11

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Patches and advisories

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected <7.0.0-38.38	Fixed in 7.0.0-38.38
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected <7.0.0-1017.17	Fixed in 7.0.0-1017.17
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected <7.0.0-1016.16	Fixed in 7.0.0-1016.16
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected <7.0.0-1008.9	Fixed in 7.0.0-1008.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and has been released in Linux kernel versions 7.0.0-1014.14~24.04.1 and later. Users and administrators should update affected Linux kernel versions to these fixed releases or later to remediate the vulnerability. No additional mitigation steps are required beyond applying the official kernel update.

Description

A vulnerability in the Linux kernel's KVM s390 subsystem allows uninitialized kernel memory to be disclosed to user space. The issue arises because the output buffer allocated by kvm_s390_get_cmma_bits() is not zeroed, leading to stale kernel memory exposure during certain migration operations. This flaw was introduced after switching to a new gmap implementation that only populates dirty pages, leaving gaps uninitialized. The vulnerability has been fixed by changing the allocation method to zero-initialize the buffer.

Impact

This vulnerability allows local users with access to the KVM s390 subsystem to read uninitialized kernel memory, potentially disclosing sensitive information. The exposure of stale kernel memory could lead to information leakage, which may aid attackers in further attacks or privilege escalation. There is no indication of remote exploitation or active exploitation in the wild.

Summary

In the Linux kernel's KVM s390 subsystem, the function kvm_s390_get_cmma_bits() allocates an output buffer using vmalloc(), which does not zero the memory. During migration, the function dat_get_cmma() reports a byte count spanning from the first to the last dirty page, but only dirty pages have their corresponding buffer entries written. Clean and unmapped pages within this range remain uninitialized, causing stale kernel memory to be copied to user space via copy_to_user(). This vulnerability was introduced with the switch to a new gmap implementation that performs a dirty-only walk, unlike the previous implementation that fully populated the buffer. The fix replaces vmalloc() with vzalloc() to ensure zero-initialization of the buffer, preventing leakage of uninitialized kernel memory.

References

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