CVE-2025-38565

Performance-counter exposure via failed mmap callback

Published Aug 19, 2025 · Updated May 11, 2026

A reference-count leak in Linux perf/core allows local users to retain x86 RDPMC access after a perf mmap allocation fails. perf_mmap() calls event_mapped() after buffer allocation failure, incrementing perf_rdpmc_allowed without a matching perf_mmap_close() decrement. Triggering the flaw requires local low-privileged access and an x86 system; the leak can leave RDPMC access enabled beyond the failed mapping.

CVSS severity2.0
Low
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A reference-count leak in Linux perf/core allows local users to retain x86 RDPMC access after a perf mmap allocation fails. perf_mmap() calls event_mapped() after buffer allocation failure, incrementing perf_rdpmc_allowed without a matching perf_mmap_close() decrement. Triggering the flaw requires local low-privileged access and an x86 system; the leak can leave RDPMC access enabled beyond the failed mapping.

The record

CVE
CVE-2025-38565
Published
Aug 19, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <07091aade394f690e7b655578140ef84d0e8d7b0
  2. Affected versionversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <163b0d1a209fe0df5476c1df2330ca12b55abf92
  3. Affected versionversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <27d44145bd576bbef9bf6165bcd78128ec3e6cbd
  4. Affected versionversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <5ffda7f3ed76ec8defc19d985e33b3b82ba07839
  5. Affected versionversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <7ff8521f30c4c2fcd4e88bd7640486602bf8a650
  6. Affected versionversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <92043120a2e992800580855498ab8507e1b22db9
  7. Affected versionversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <9b90a48c7de828a15c7a4fc565d46999c6e22d6b
  8. Affected versionversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <de85e72598d89880a02170a1cbc27b35a7d978a9
  9. Affected versionversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <f41e9eba77bf97626e04296dc5677d02816d2432
  10. Affected versionversion=4.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <07091aade394f690e7b655578140ef84d0e8d7b0; version=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <163b0d1a209fe0df5476c1df2330ca12b55abf92; version=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <27d44145bd576bbef9bf6165bcd78128ec3e6cbd; version=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <5ffda7f3ed76ec8defc19d985e33b3b82ba07839; version=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <7ff8521f30c4c2fcd4e88bd7640486602bf8a650; version=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <92043120a2e992800580855498ab8507e1b22db9; version=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <9b90a48c7de828a15c7a4fc565d46999c6e22d6b; version=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <de85e72598d89880a02170a1cbc27b35a7d978a9; version=1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb <f41e9eba77bf97626e04296dc5677d02816d2432; version=4.0

Published CVSS scores

2.0Canonical UbuntuCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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