CVE-2026-89837

Kernel memory leak via unreleased dentry folio

Published Sep 16, 2026 · Updated Sep 16, 2026

A folio reference leak in the f2fs directory lookup path in Linux allows attackers to consume kernel memory through lookup errors. find_in_level() obtains a dentry folio before calling find_in_block() but fails to release it when that call returns an error. Reachability requires an f2fs directory lookup that drives find_in_block() into its error path; the published record establishes neither remote reachability nor an impact beyond leaked kernel memory.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A folio reference leak in the f2fs directory lookup path in Linux allows attackers to consume kernel memory through lookup errors. find_in_level() obtains a dentry folio before calling find_in_block() but fails to release it when that call returns an error. Reachability requires an f2fs directory lookup that drives find_in_block() into its error path; the published record establishes neither remote reachability nor an impact beyond leaked kernel memory.

The record

CVE
CVE-2026-89837
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=5.11
  2. Affected versionversion=7ad08a58bf67594057362e45cbddd3e27e53e557 <93a3e6a4c9e726a13a935963e8dc43d181db1527
  3. Affected versionversion=7ad08a58bf67594057362e45cbddd3e27e53e557 <aefb4b0f465b6f95fe02b52d1822a3fb4a9ae922
  4. Affected versionversion=7ad08a58bf67594057362e45cbddd3e27e53e557 <cca7d3e30bf30333314e31bc70b9a739f1342167

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.11; version=7ad08a58bf67594057362e45cbddd3e27e53e557 <93a3e6a4c9e726a13a935963e8dc43d181db1527; version=7ad08a58bf67594057362e45cbddd3e27e53e557 <aefb4b0f465b6f95fe02b52d1822a3fb4a9ae922; version=7ad08a58bf67594057362e45cbddd3e27e53e557 <cca7d3e30bf30333314e31bc70b9a739f1342167

Published CVSS scores

No CVSS assessment is available in this record.

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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