VulnerabilityPublished 23 Oct 2026

CVE-2026-99067: Linux kernel · btrfs: scrub: fix local_root reference leak in scrub_print_warning_inode()

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in a7e5992bc37088f9b00e531955022aef69de3dc7 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Low

Rated Low by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in a7e5992bc37088f9b00e531955022aef69de3dc7, 452a435b74f7f598a343c51f7c89c5d2244384b6, 41cabfbf3532e2a2a17be9e4876042a5393b5c8d +2

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 558540c17771eaf89b1a3be39aa2c8bc837da1a6, < a7e5992bc37088f9b00e531955022aef69de3dc7	Fixed in a7e5992bc37088f9b00e531955022aef69de3dc7
LinuxLinux	Affected ≥ 558540c17771eaf89b1a3be39aa2c8bc837da1a6, < 452a435b74f7f598a343c51f7c89c5d2244384b6	Fixed in 452a435b74f7f598a343c51f7c89c5d2244384b6
LinuxLinux	Affected ≥ 558540c17771eaf89b1a3be39aa2c8bc837da1a6, < 41cabfbf3532e2a2a17be9e4876042a5393b5c8d	Fixed in 41cabfbf3532e2a2a17be9e4876042a5393b5c8d
LinuxLinux	Affected ≥ 558540c17771eaf89b1a3be39aa2c8bc837da1a6, < 12ba7d8b9cd45a2c6aa8f37c3f4b8a50422fb549	Fixed in 12ba7d8b9cd45a2c6aa8f37c3f4b8a50422fb549
LinuxLinux	Affected ≥ 558540c17771eaf89b1a3be39aa2c8bc837da1a6, < 1fd742c7479961da6d0bb794ef8ac6b7b9442847	Fixed in 1fd742c7479961da6d0bb794ef8ac6b7b9442847
LinuxLinux	Affected =3.2	Fixed in–

AI-suggested

The vulnerability has been fixed in the Linux kernel. Users should update to a kernel version that includes the fix identified by the commits a7e5992bc37088f9b00e531955022aef69de3dc7, 452a435b74f7f598a343c51f7c89c5d2244384b6, 41cabfbf3532e2a2a17be9e4876042a5393b5c8d, 12ba7d8b9cd45a2c6aa8f37c3f4b8a50422fb549, or 1fd742c7479961da6d0bb794ef8ac6b7b9442847. No other mitigation or workaround is indicated.

Description

A reference leak vulnerability was identified and fixed in the Linux kernel's btrfs filesystem scrub functionality. Specifically, the function scrub_print_warning_inode() failed to drop a reference to the root when paths_from_inode() failed, causing a local_root reference leak. This leak occurred each time path resolution failed during scrub warning printing. The issue has been corrected by ensuring the reference is properly dropped on the failure path.

Impact

The vulnerability causes a local reference leak in the kernel's btrfs scrub functionality. While this does not directly lead to privilege escalation or remote code execution, leaking kernel references can degrade system stability or lead to resource exhaustion over time if the condition occurs frequently. There is no indication of active exploitation or broader impact beyond resource management.

Summary

CVE-2026-99067 addresses a reference leak in the Linux kernel's btrfs scrub code. When the function paths_from_inode() fails, scrub_print_warning_inode() erroneously jumps to an error handling path without releasing a reference acquired by btrfs_get_fs_root(), resulting in a local_root reference leak. All other code paths correctly release this reference. The fix ensures the reference is dropped even when paths_from_inode() fails, preventing resource leakage during scrub warning printing.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:00 UTC

Technical details

References

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