CVE-2025-40333

Kernel hang via unterminated extent-tree lookup

Published Dec 9, 2025 · Updated May 11, 2026

Affected Linux kernel F2FS releases allow attackers to hang the kernel via malformed extent data during extent-tree insertion. The __insert_extent_tree() overlap branch reports an invariant failure but fails to leave its red-black-tree search loop. The loop requires corrupted or zero-length extent information and disabled CONFIG_F2FS_CHECK_FS; public sources do not establish how attackers supply that state.

CVSS severityUnavailable
Unscored
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Affected Linux kernel F2FS releases allow attackers to hang the kernel via malformed extent data during extent-tree insertion. The __insert_extent_tree() overlap branch reports an invariant failure but fails to leave its red-black-tree search loop. The loop requires corrupted or zero-length extent information and disabled CONFIG_F2FS_CHECK_FS; public sources do not establish how attackers supply that state.

The record

CVE
CVE-2025-40333
Published
Dec 9, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=3.8
  2. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <23361bd54966b437e1ed3eb1a704572f4b279e58
  3. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <765f8816d3959ef1f3f7f85e2af748594d091f40
  4. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <c0b9951bb2668d67eb4817bb23fc109abc08c075
  5. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <f4c31adcb2a0556f43776d4e51a67de88d7fb9ee

What conditions does exploitation require?

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

What is affected?

The Linux Kernel Organization · Linuxversion=3.8; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <23361bd54966b437e1ed3eb1a704572f4b279e58; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <765f8816d3959ef1f3f7f85e2af748594d091f40; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <c0b9951bb2668d67eb4817bb23fc109abc08c075; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <f4c31adcb2a0556f43776d4e51a67de88d7fb9ee

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.

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)
VectorUnavailable
PrivilegesUnavailable
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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