CVE-2026-74315Network attack vector

NLM lock-state interruption via uninitialized handle hashing

Published Aug 15, 2026 · Updated Aug 15, 2026

Use of uninitialized data in Linux kernel lockd 7.1 allows remote attackers to disrupt NLMv4 lock-state lookups via short file handles. The nlm4svc_lookup_file() path copies only the supplied handle length, while file_hash() always digests 32 bytes, so stale tail bytes change the bucket for the same handle. An NLMv4 client that can reach lockd can make existing nlm_file entries appear missing, interrupting lock-state operations without crashing the host.

CVSS severity9.8
Critical
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of uninitialized data in Linux kernel lockd 7.1 allows remote attackers to disrupt NLMv4 lock-state lookups via short file handles. The nlm4svc_lookup_file() path copies only the supplied handle length, while file_hash() always digests 32 bytes, so stale tail bytes change the bucket for the same handle. An NLMv4 client that can reach lockd can make existing nlm_file entries appear missing, interrupting lock-state operations without crashing the host.

The record

CVE
CVE-2026-74315
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-665, CWE-908, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=3de744ee4e4557da0d63be8a97ad44b4dad58912 <686c2434f9f16b87aeed18d76cc562df9f2695ab
  2. Affected versionversion=3de744ee4e4557da0d63be8a97ad44b4dad58912 <6e4c62caecf792e8a15ad9bc7f371e57c17e3302
  3. Affected versionversion=7.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3de744ee4e4557da0d63be8a97ad44b4dad58912 <686c2434f9f16b87aeed18d76cc562df9f2695ab; version=3de744ee4e4557da0d63be8a97ad44b4dad58912 <6e4c62caecf792e8a15ad9bc7f371e57c17e3302; version=7.1

Published CVSS scores

7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
9.8CVE.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
4.8Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-665Improper Initialization
CWE-908Use of Uninitialized Resource
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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