CVE-2024-26629Network attack vector

NFS lock failure via transient reference count

Published Mar 13, 2024 · Updated May 23, 2026

Incorrect status handling in Linux NFSD allows attackers to disrupt NFSv4 lock-owner state through concurrent LOCK and RELEASE requests. nfsd4_release_lockowner() compares the transient so_count reference total with two and returns NFS4ERR_LOCKS_HELD even when no locks remain. Reachability requires NFSv4 request access; reuse of the retained owner with sequence zero produces NFS4ERR_BAD_SEQID and prevents correct locking.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect status handling in Linux NFSD allows attackers to disrupt NFSv4 lock-owner state through concurrent LOCK and RELEASE requests. nfsd4_release_lockowner() compares the transient so_count reference total with two and returns NFS4ERR_LOCKS_HELD even when no locks remain. Reachability requires NFSv4 request access; reuse of the retained owner with sequence zero produces NFS4ERR_BAD_SEQID and prevents correct locking.

The record

CVE
CVE-2024-26629
Published
Mar 13, 2024
Updated
May 23, 2026
Vendor
Siemens
Product
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Classifications
CWE-393, T1499
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Mar 13, 2024CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=0 <*

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
The Linux Kernel Organization · Linuxversion=2ec65dc6635d1976bd1dbf2640ff7f810b2f6dd1; version=3097f38e91266c7132c3fdb7e778fac858c00670 <99fb654d01dc3f08b5905c663ad6c89a9d83302f; version=4.14.282 <4.15; version=4.19.246 <4.19.306; version=4.9.317 <4.10; version=5.10.120 <5.10.220; version=5.15.45 <5.15.154; version=5.17.13 <5.18; version=5.18.2 <5.19; version=5.19; version=5.4.197 <5.5; version=a2235bc65ade40982c3d09025cdd34bc539d6a69; version=ba747abfca27e23c42ded3912c87b70d7e16b6ab; version=ce3c4ad7f4ce5db7b4f08a1e237d8dd94b39180b <8f5b860de87039b007e84a28a5eefc888154e098; version=ce3c4ad7f4ce5db7b4f08a1e237d8dd94b39180b <b7d2eee1f53899b53f069bba3a59a419fc3d331b; version=ce3c4ad7f4ce5db7b4f08a1e237d8dd94b39180b <e4cf8941664cae2f89f0189c29fe2ce8c6be0d03; version=ce3c4ad7f4ce5db7b4f08a1e237d8dd94b39180b <edcf9725150e42beeca42d085149f4c88fa97afd; version=e2fc17fcc503cfca57b5d1dd3b646ca7eebead97 <c6f8b3fcc62725e4129f2c0fd550d022d4a7685a; version=e8020d96dd5b2dcc1f6a8ee4f87a53a373002cd5; version=ef481b262bba4f454351eec43f024fec942c2d4c <10d75984495f7fe62152c3b0dbfa3f0a6b739c9b; version=fea1d0940301378206955264a01778700fc9c16f

Published CVSS scores

5.5Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-393Return of Wrong Status Code
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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