Linux Kernel up to 7.1.4 lockd nlm_do_fopen reference count

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.50-

Summaryinfo

A vulnerability has been found in Linux Kernel up to 7.1.4 and classified as very critical. This affects the function nlm_do_fopen of the component lockd. This manipulation causes reference count. This vulnerability appears as CVE-2026-72218. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 7.1.4. Affected by this vulnerability is the function nlm_do_fopen of the component lockd. The manipulation with an unknown input leads to a reference count vulnerability. The CWE definition for the vulnerability is CWE-911. The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: lockd: Plug nlm_file refcount leak on cached nlm_do_fopen() failure The cached-file path in nlm_lookup_file() reaches the found: label unconditionally, even when nlm_do_fopen() fails. At that label *result and file->f_count are updated before the error is returned. The wrappers nlm3svc_lookup_file() and nlm4svc_lookup_file() then bail out of their switch without copying *result back to their caller, so the proc handler's local nlm_file pointer remains NULL and the cleanup path skips nlm_release_file(). The f_count increment is never released, and nlm_traverse_files() can no longer reap the file because its refcount never returns to zero between requests. Short-circuit the cached path so neither *result nor f_count is touched when nlm_do_fopen() fails on a hashed nlm_file.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-72218 since 08/09/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/15/2026).

Upgrading to version 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5 or 7.2-rc1 eliminates this vulnerability. Applying the patch 6cd84cefd8b73e85b9eda17b319bd40a670f3a38/fe3b45b56b6c3d4b6b341de27fa291005287a21c/cb3420c047957e565101585bb4f15e1a6e3de6b0/7ce4c23e783e766507b2cef27bbf97e9ca944f1a/84008bf1860e0ef8059a7583a1163f36b704d08a/46d59ff421824b6483549d87f14efffbbbd1f6cb/3a5c55a19cad62f2973be25fe96a1a9e7f618e8a/70a38f87bed7f0694fd07988b47b2db1e10d8df3 is able to eliminate this problem.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Reference count
CWE: CWE-911 / CWE-664
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.261/5.15.212/6.1.178/6.6.145/6.12.97/6.18.40/7.1.5/7.2-rc1
Patch: 6cd84cefd8b73e85b9eda17b319bd40a670f3a38/fe3b45b56b6c3d4b6b341de27fa291005287a21c/cb3420c047957e565101585bb4f15e1a6e3de6b0/7ce4c23e783e766507b2cef27bbf97e9ca944f1a/84008bf1860e0ef8059a7583a1163f36b704d08a/46d59ff421824b6483549d87f14efffbbbd1f6cb/3a5c55a19cad62f2973be25fe96a1a9e7f618e8a/70a38f87bed7f0694fd07988b47b2db1e10d8df3

Timelineinfo

08/09/2026 CVE reserved
08/15/2026 +6 days Advisory disclosed
08/15/2026 +0 days VulDB entry created
08/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-72218 (🔒)
GCVE (CVE): GCVE-0-2026-72218
GCVE (VulDB): GCVE-100-390673

Entryinfo

Created: 08/15/2026 13:53
Changes: 08/15/2026 13:53 (59)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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