CVE-2026-64556

Kernel memory corruption via stale perf group state

Published Jul 29, 2026 · Updated Jul 29, 2026

Memory corruption in Linux Kernel 5.13 allows local users to corrupt PMU context lists through perf event group teardown. perf_event_remove_on_exec() detaches an active group leader with DETACH_EXIT but leaves surviving siblings linked to the removed leader, allowing merge_sched_in() to add an already-linked active_list entry. A local user must create a mixed remove_on_exec group, execute the teardown sequence, close the leader, and reschedule it; the double-add allows compromise of kernel confidentiality, integrity, and availability.

CVSS severity7.8
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Memory corruption in Linux Kernel 5.13 allows local users to corrupt PMU context lists through perf event group teardown. perf_event_remove_on_exec() detaches an active group leader with DETACH_EXIT but leaves surviving siblings linked to the removed leader, allowing merge_sched_in() to add an already-linked active_list entry. A local user must create a mixed remove_on_exec group, execute the teardown sequence, close the leader, and reschedule it; the double-add allows compromise of kernel confidentiality, integrity, and availability.

The record

CVE
CVE-2026-64556
Published
Jul 29, 2026
Updated
Jul 29, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 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=2e498d0a74e5b88a6689ae1b811f247f91ff188e <037a3c43edfb597665dd34457cd22b14692f2ba3
  2. Affected versionversion=2e498d0a74e5b88a6689ae1b811f247f91ff188e <06ccef0434e98058ddae7bcebc901f93d22b7653
  3. Affected versionversion=2e498d0a74e5b88a6689ae1b811f247f91ff188e <39358e856fb89e62e3c8d7389a2dc4ec33dbe90e
  4. Affected versionversion=2e498d0a74e5b88a6689ae1b811f247f91ff188e <4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2
  5. Affected versionversion=2e498d0a74e5b88a6689ae1b811f247f91ff188e <a2d5d3ee7b6e3953114726b1521e62123ab5b043
  6. Affected versionversion=5.13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2e498d0a74e5b88a6689ae1b811f247f91ff188e <037a3c43edfb597665dd34457cd22b14692f2ba3; version=2e498d0a74e5b88a6689ae1b811f247f91ff188e <06ccef0434e98058ddae7bcebc901f93d22b7653; version=2e498d0a74e5b88a6689ae1b811f247f91ff188e <39358e856fb89e62e3c8d7389a2dc4ec33dbe90e; version=2e498d0a74e5b88a6689ae1b811f247f91ff188e <4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2; version=2e498d0a74e5b88a6689ae1b811f247f91ff188e <a2d5d3ee7b6e3953114726b1521e62123ab5b043; version=5.13

Published CVSS scores

7.8kernel.orgCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

T1068Exploitation for Privilege Escalation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo