CVE-2026-74571

Kernel crash via missing rescue-mount root

Published Aug 15, 2026 · Updated Aug 15, 2026

NULL pointer dereference in Btrfs in the Linux kernel allows local users to crash the kernel while mounting a corrupted filesystem. btrfs_read_roots continues after an unreadable block-group or RAID-stripe-tree root, leaving its pointer NULL while its feature bit remains set; btrfs_update_global_block_rsv then dereferences that pointer. The user must hold high local privileges, supply a filesystem with either corrupted root, and mount it with rescue=ibadroots.

CVSS severity4.4
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Btrfs in the Linux kernel allows local users to crash the kernel while mounting a corrupted filesystem. btrfs_read_roots continues after an unreadable block-group or RAID-stripe-tree root, leaving its pointer NULL while its feature bit remains set; btrfs_update_global_block_rsv then dereferences that pointer. The user must hold high local privileges, supply a filesystem with either corrupted root, and mount it with rescue=ibadroots.

The record

CVE
CVE-2026-74571
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=1e8087589b5cf6fa17adaf57b64cf1656d77dfec
  2. Affected versionversion=6.1.43 <6.2
  3. Affected versionversion=6.4.8 <6.5
  4. Affected versionversion=6.5
  5. Affected versionversion=8dbfc14fc736eb701089aff09645c3d4ad3decb1 <076349e4c8d11f6b58c4549976a513b2b4dc6df2
  6. Affected versionversion=8dbfc14fc736eb701089aff09645c3d4ad3decb1 <51a0e8399858621442807a26057bcd1cd3ced046
  7. Affected versionversion=cbec34d3021d47007a0334c634f7053dbaf93d02

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=1e8087589b5cf6fa17adaf57b64cf1656d77dfec; version=6.1.43 <6.2; version=6.4.8 <6.5; version=6.5; version=8dbfc14fc736eb701089aff09645c3d4ad3decb1 <076349e4c8d11f6b58c4549976a513b2b4dc6df2; version=8dbfc14fc736eb701089aff09645c3d4ad3decb1 <51a0e8399858621442807a26057bcd1cd3ced046; version=cbec34d3021d47007a0334c634f7053dbaf93d02

Published CVSS scores

4.4Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/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.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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