VulnerabilityPublished 17 Sep 2026Updated 23 Sep 2026

CVE-2026-93197: Linux kernel · memcg: move LRU size accounting on reparenting instead of copying it

Affects Linux kernelSource GCVE Database

Authoritative record:CVE-2026-93197· Medium

Not known to be exploited.

Data as of 26 Oct 2026, 14:05 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.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Sep 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

Affected software

Product	Affected	Fixed in
Ubuntu 24.04 LTSlinux-aws-6.14`pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=noble`Other threats	Affected 6.14.0-1007.7~24.04.1 – 6.14.0-1018.18~24.04.1 11 affected builds	Fixed in–
Ubuntu 24.04 LTSlinux-aws-6.17`pkg:deb/ubuntu/linux-aws-6.17?arch=source&distro=noble`Other threats	Affected 6.17.0-1005.5~24.04.2 – 6.17.0-1020.20~24.04.1 10 affected builds	Fixed in–
Ubuntu 24.04 LTSlinux-azure-6.11`pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=noble`Other threats	Affected 6.11.0-1008.8~24.04.1 – 6.11.0-1018.18~24.04.1 7 affected builds	Fixed in–
Ubuntu 24.04 LTSlinux-azure-6.14`pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=noble`Other threats	Affected 6.14.0-1010.10~24.04.1 – 6.14.0-1017.17~24.04.1 5 affected builds	Fixed in–
Ubuntu 24.04 LTSlinux-azure-6.17`pkg:deb/ubuntu/linux-azure-6.17?arch=source&distro=noble`Other threats	Affected 6.17.0-1008.8~24.04.1 – 6.17.0-1022.22 10 affected builds	Fixed in–
Ubuntu 24.04 LTSlinux-azure-fde-6.14`pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=noble`Other threats	Affected 6.14.0-1012.12~24.04.1 – 6.14.0-1017.17~24.04.1 5 affected builds	Fixed in–

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

AI-suggested

A fix for this vulnerability is available in updated Linux kernel versions that move the LRU size accounting on reparenting instead of copying it, properly clearing the child's counters. Users should apply the official kernel updates corresponding to their distributions and kernel versions. Since this is a kernel-level fix, upgrading to a patched kernel version is the recommended remediation. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's memory control group (memcg) subsystem involves incorrect handling of Least Recently Used (LRU) size accounting during reparenting of memory cgroups. Specifically, when a memory cgroup is offlined, its LRU folios are reparented to the parent cgroup, but the child's LRU size counters are not cleared, causing stale size values to persist. This leads to inaccurate accounting and potential resource mismanagement. The issue affects multiple Linux kernel versions and has been resolved in updated kernel releases.

Impact

The vulnerability causes inaccurate memory usage accounting in memory cgroups, leading to stale LRU size counters on offlined (dying) cgroups. This results in scanning loops processing empty lists and over-budgeting shadow node limits, which can cause inefficient memory management and resource waste. On large systems, this can manifest as inflated memory usage statistics and potential performance degradation due to unnecessary scanning. There is no indication of direct security compromise or code execution from this issue.

Summary

The vulnerability in the Linux kernel memcg subsystem arises from the function lruvec_reparent_lru() splicing the child's LRU lists into the parent's and crediting the parent with the child's per-zone lru_zone_size[], but failing to clear the child's copy. This causes the child's stale LRU size counters to remain, leading to incorrect accounting. The stale counters cause scanning functions like mem_cgroup_iter() and shrink_lruvec() to operate inefficiently on dead cgroups, potentially causing excessive resource usage. The issue also affects MGLRU and the LRU_UNEVICTABLE size accounting. The flaw depends on a specific kernel commit and must not be backported prematurely. The vulnerability has been resolved by moving the LRU size accounting on reparenting instead of copying it, ensuring the child's counters are cleared properly.

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What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Oct 2026, 23:59 UTC

Technical details

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