VulnerabilityPublished 15 Aug 2026Updated 9 Oct 2026

CVE-2026-72218: Linux kernel · lockd: Plug nlm_file refcount leak on cached nlm_do_fopen() failure

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +41

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.

ghsa-mwwg-vq2v-v2c8

What to do

Upgrade to a fixed release listed under Affected software.

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 should be applied to affected Linux kernel versions to resolve the reference count leak. The vendor advisory confirms the issue is fixed. No additional mitigation actions are required beyond applying the official update.

Description

A vulnerability in the Linux kernel's lockd component caused a reference count leak when nlm_do_fopen() failed during cached file operations. This flaw prevented proper cleanup of file references, potentially leading to resource exhaustion. The issue has been resolved with a patch that short-circuits the cached path to avoid incrementing reference counts on failure.

Impact

The vulnerability causes a reference count leak in the lockd subsystem of the Linux kernel, which can lead to resource exhaustion as file references are not properly released. This may degrade system stability or performance over time but does not directly allow code execution or privilege escalation.

Summary

The Linux kernel vulnerability (CVE-2026-72218) involves the lockd subsystem where a reference count leak occurs on cached nlm_do_fopen() failure. Specifically, the cached-file path in nlm_lookup_file() updates the result pointer and file reference count even when nlm_do_fopen() fails. Subsequent functions bail out without copying the result back, causing the local nlm_file pointer to remain NULL and skipping the release of the file reference. This results in the reference count never decrementing, preventing nlm_traverse_files() from reclaiming the file. The fix short-circuits the cached path to avoid touching the result or reference count when nlm_do_fopen() fails.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Oct 2026, 07:36 UTC

Technical details

References

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