CVE-2026-23053

System hang via synchronous NFS folio writeback

Published Feb 4, 2026 · Updated Feb 4, 2026

Denial of service in the Linux Kernel NFS client allows attackers to hang systems during NFSv4.1 state recovery over a network. The nfs_release_folio() reclaim path calls nfs_wb_folio(), whose synchronous writeback waits for NFS state recovery that is itself blocked on kthreadd reclaim. Reachability requires an affected kernel acting as an NFSv4.1 client, state recovery, and concurrent memory reclaim; the bounded consequence is a deadlock that interrupts service.

CVSS severity5.3
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux Kernel NFS client allows attackers to hang systems during NFSv4.1 state recovery over a network. The nfs_release_folio() reclaim path calls nfs_wb_folio(), whose synchronous writeback waits for NFS state recovery that is itself blocked on kthreadd reclaim. Reachability requires an affected kernel acting as an NFSv4.1 client, state recovery, and concurrent memory reclaim; the bounded consequence is a deadlock that interrupts service.

The record

CVE
CVE-2026-23053
Published
Feb 4, 2026
Updated
Feb 4, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 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=6.3
  2. Affected versionversion=96780ca55e3cbf4f150fd5a833a61492c9947b5b <19b4d9ab5e77843eac0429c019470c02f8710b55
  3. Affected versionversion=96780ca55e3cbf4f150fd5a833a61492c9947b5b <49d352bc263fe4a834233338bfaad31b3109addf
  4. Affected versionversion=96780ca55e3cbf4f150fd5a833a61492c9947b5b <cce0be6eb4971456b703aaeafd571650d314bcca

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.3; version=96780ca55e3cbf4f150fd5a833a61492c9947b5b <19b4d9ab5e77843eac0429c019470c02f8710b55; version=96780ca55e3cbf4f150fd5a833a61492c9947b5b <49d352bc263fe4a834233338bfaad31b3109addf; version=96780ca55e3cbf4f150fd5a833a61492c9947b5b <cce0be6eb4971456b703aaeafd571650d314bcca

Published CVSS scores

5.3OracleCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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