CVE-2025-23138

Local pipe-allocation denial via accounting underflow

Published Apr 16, 2025 · Updated May 23, 2026

Integer underflow in Linux kernel watch queues allows local users to block subsequent pipe-buffer allocations with an EPERM error. watch_queue_set_size() charges user->pipe_bufs without synchronizing pipe->nr_accounted, so freeing the pipe subtracts a different buffer count and can underflow the user accounting. Exploitation requires low-privileged local access and watch-queue pipe creation; the reported consequence is denial of later pipe-buffer allocations, not a kernel crash or data compromise.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in Linux kernel watch queues allows local users to block subsequent pipe-buffer allocations with an EPERM error. watch_queue_set_size() charges user->pipe_bufs without synchronizing pipe->nr_accounted, so freeing the pipe subtracts a different buffer count and can underflow the user accounting. Exploitation requires low-privileged local access and watch-queue pipe creation; the reported consequence is denial of later pipe-buffer allocations, not a kernel crash or data compromise.

The record

CVE
CVE-2025-23138
Published
Apr 16, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-191, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 16, 2025CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=162ae0e78bdabf84ef10c1293c4ed7865cb7d3c8 <8658c75343ed00e5e154ebbe24335f51ba8db547
  2. Affected versionversion=3efbd114b91525bb095b8ae046382197d92126b9 <471c89b7d4f58bd6082f7c1fe14d4ca15c7f1284
  3. Affected versionversion=5.10.210 <5.10.236
  4. Affected versionversion=5.15.149 <5.15.180
  5. Affected versionversion=6.1.76 <6.1.134
  6. Affected versionversion=6.6.15 <6.6.87
  7. Affected versionversion=6.7.3 <6.8
  8. Affected versionversion=6.8
  9. Affected versionversion=68e51bdb1194f11d3452525b99c98aff6f837b24 <6dafa27764183738dc5368b669b71e3d0d154f12
  10. Affected versionversion=6fb70694f8d1ac34e45246b0ac988f025e1e5b55
  11. Affected versionversion=b87a1229d8668fbc78ebd9ca0fc797a76001c60f <d40e3537265dea9e3c33021874437ff26dc18787
  12. Affected versionversion=e95aada4cb93d42e25c30a0ef9eb2923d9711d4a <205028ebba838938d3b264dda1d0708fa7fe1ade
  13. Affected versionversion=e95aada4cb93d42e25c30a0ef9eb2923d9711d4a <2d680b988656bb556c863d8b46d9b9096842bf3d
  14. Affected versionversion=e95aada4cb93d42e25c30a0ef9eb2923d9711d4a <56ec918e6c86c1536870e4373e91eddd0c44245f
  15. Affected versionversion=e95aada4cb93d42e25c30a0ef9eb2923d9711d4a <f13abc1e8e1a3b7455511c4e122750127f6bc9b0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=162ae0e78bdabf84ef10c1293c4ed7865cb7d3c8 <8658c75343ed00e5e154ebbe24335f51ba8db547; version=3efbd114b91525bb095b8ae046382197d92126b9 <471c89b7d4f58bd6082f7c1fe14d4ca15c7f1284; version=5.10.210 <5.10.236; version=5.15.149 <5.15.180; version=6.1.76 <6.1.134; version=6.6.15 <6.6.87; version=6.7.3 <6.8; version=6.8; version=68e51bdb1194f11d3452525b99c98aff6f837b24 <6dafa27764183738dc5368b669b71e3d0d154f12; version=6fb70694f8d1ac34e45246b0ac988f025e1e5b55; version=b87a1229d8668fbc78ebd9ca0fc797a76001c60f <d40e3537265dea9e3c33021874437ff26dc18787; version=e95aada4cb93d42e25c30a0ef9eb2923d9711d4a <205028ebba838938d3b264dda1d0708fa7fe1ade; version=e95aada4cb93d42e25c30a0ef9eb2923d9711d4a <2d680b988656bb556c863d8b46d9b9096842bf3d; version=e95aada4cb93d42e25c30a0ef9eb2923d9711d4a <56ec918e6c86c1536870e4373e91eddd0c44245f; version=e95aada4cb93d42e25c30a0ef9eb2923d9711d4a <f13abc1e8e1a3b7455511c4e122750127f6bc9b0

Published CVSS scores

5.5UbuntuCVSS: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

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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