CVE-2026-68442

Kernel memory corruption via inherited logging flag

Published Aug 12, 2026 · Updated Aug 12, 2026

Use-after-free in Linux btrfs allows local users to disclose or corrupt kernel memory through concurrent operations on a writable file. btrfs_drop_extent_map_range() clears EXTENT_FLAG_LOGGING on em->flags rather than the local flags copy, leaving a split extent map linked after it is freed. Write access to a btrfs filesystem is required; repeated fsync and range-changing operations can produce a kernel panic or support privilege escalation.

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

What happened

Use-after-free in Linux btrfs allows local users to disclose or corrupt kernel memory through concurrent operations on a writable file. btrfs_drop_extent_map_range() clears EXTENT_FLAG_LOGGING on em->flags rather than the local flags copy, leaving a split extent map linked after it is freed. Write access to a btrfs filesystem is required; repeated fsync and range-changing operations can produce a kernel panic or support privilege escalation.

The record

CVE
CVE-2026-68442
Published
Aug 12, 2026
Updated
Aug 12, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-825, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 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=6.8
  2. Affected versionversion=f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <0e465c63f103a5ce6849614d6bda048d70eebec8
  3. Affected versionversion=f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <2a9246a424f45f33a1b8367052611ebe874868ad
  4. Affected versionversion=f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <5eff4d5b17fa1950e80bfd1ba43dc0699e61a644
  5. Affected versionversion=f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <9304713b70e7e1450e3a76e758836fe5391bfa95

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.8; version=f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <0e465c63f103a5ce6849614d6bda048d70eebec8; version=f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <2a9246a424f45f33a1b8367052611ebe874868ad; version=f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <5eff4d5b17fa1950e80bfd1ba43dc0699e61a644; version=f86f7a75e2fb5fd7d31d00eab8a392f97ba42ce9 <9304713b70e7e1450e3a76e758836fe5391bfa95

Published CVSS scores

7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Linux Kernel CVE TeamCVSS: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 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-825Expired Pointer Dereference
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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