CVE-2026-64375

Local privilege escalation via racy procfs task lookup

Published Jul 25, 2026 · Updated Jul 25, 2026

A TOCTOU race in Linux Kernel procfs allows local users to gain root privileges through file descriptor links during privileged execution. proc_pid_get_link() and proc_pid_readlink() check one task, then perform a second unlocked PID lookup, allowing a same-UID child to exec setuid between check and use. A basic unprivileged account can repeatedly race a launched setuid program, redirect access to its post-exec memfd, and read or alter privileged contents for root-level execution.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A TOCTOU race in Linux Kernel procfs allows local users to gain root privileges through file descriptor links during privileged execution. proc_pid_get_link() and proc_pid_readlink() check one task, then perform a second unlocked PID lookup, allowing a same-UID child to exec setuid between check and use. A basic unprivileged account can repeatedly race a launched setuid program, redirect access to its post-exec memfd, and read or alter privileged contents for root-level execution.

The record

CVE
CVE-2026-64375
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-367, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 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=2.6.18
  2. Affected versionversion=778c1144771f0064b6f51bee865cceb0d996f2f9 <138c692d2b2d63d26f2eb957d0e4fcc5d61f9ff2
  3. Affected versionversion=778c1144771f0064b6f51bee865cceb0d996f2f9 <497c6bae5167428596575f20af6613ff5671f383
  4. Affected versionversion=778c1144771f0064b6f51bee865cceb0d996f2f9 <6253dfee5afba536bb54fc6fe6c091c3758fafe1
  5. Affected versionversion=778c1144771f0064b6f51bee865cceb0d996f2f9 <6255da28d4bb5349fe18e84cb043ccd394eba75d
  6. Affected versionversion=778c1144771f0064b6f51bee865cceb0d996f2f9 <65bf0d2b6e914f1448d6a2fde193dcf60936a651
  7. Affected versionversion=778c1144771f0064b6f51bee865cceb0d996f2f9 <83b17872e3166c295c599279fc9562ac3840c638
  8. Affected versionversion=778c1144771f0064b6f51bee865cceb0d996f2f9 <de497d7aa2fae453a7e7c8f7d3e8682e565e3aaf
  9. Affected versionversion=778c1144771f0064b6f51bee865cceb0d996f2f9 <dfd1894cb64cbd8758b461ed713800fe73db4f82

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.18; version=778c1144771f0064b6f51bee865cceb0d996f2f9 <138c692d2b2d63d26f2eb957d0e4fcc5d61f9ff2; version=778c1144771f0064b6f51bee865cceb0d996f2f9 <497c6bae5167428596575f20af6613ff5671f383; version=778c1144771f0064b6f51bee865cceb0d996f2f9 <6253dfee5afba536bb54fc6fe6c091c3758fafe1; version=778c1144771f0064b6f51bee865cceb0d996f2f9 <6255da28d4bb5349fe18e84cb043ccd394eba75d; version=778c1144771f0064b6f51bee865cceb0d996f2f9 <65bf0d2b6e914f1448d6a2fde193dcf60936a651; version=778c1144771f0064b6f51bee865cceb0d996f2f9 <83b17872e3166c295c599279fc9562ac3840c638; version=778c1144771f0064b6f51bee865cceb0d996f2f9 <de497d7aa2fae453a7e7c8f7d3e8682e565e3aaf; version=778c1144771f0064b6f51bee865cceb0d996f2f9 <dfd1894cb64cbd8758b461ed713800fe73db4f82

Published CVSS scores

7.8Linux kernel CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/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 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

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
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

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Your stack

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