CVE-2025-38218

Kernel panic via undersized F2FS SIT bitmap

Published Jul 4, 2025 · Updated Aug 5, 2026

Denial of service in the Linux kernel F2FS implementation allows local users to panic the kernel by mounting a malformed filesystem image. f2fs_sanity_check_ckpt() fails to reject a checkpoint whose SIT bitmap is too small for its declared segment count, so current_sit_addr() reads beyond the bitmap and f2fs_bug_on() aborts the kernel. Triggering the flaw requires privileges to mount a crafted F2FS image and interrupts the host rather than a remote service.

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

What happened

Denial of service in the Linux kernel F2FS implementation allows local users to panic the kernel by mounting a malformed filesystem image. f2fs_sanity_check_ckpt() fails to reject a checkpoint whose SIT bitmap is too small for its declared segment count, so current_sit_addr() reads beyond the bitmap and f2fs_bug_on() aborts the kernel. Triggering the flaw requires privileges to mount a crafted F2FS image and interrupts the host rather than a remote service.

The record

CVE
CVE-2025-38218
Published
Jul 4, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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 <38ef48a8afef8df646b6f6ae7abb872f18b533c1
  3. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <3e5ac62a56a24f4d88ce8ffd7bc452428b235868
  4. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <5db0d252c64e91ba1929c70112352e85dc5751e7
  5. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <79ef8a6c4ec53d327580fd7d2b522cf4f1d05b0c
  6. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <82f51bff393e4c12cf4de553120ca831cfa4ef19
  7. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <ad862f71016ba38039df1c96ed55c0a4314cc183
  8. Affected versionversion=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <ee1b421c469876544e297ec1090574bd76100247

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.8; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <38ef48a8afef8df646b6f6ae7abb872f18b533c1; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <3e5ac62a56a24f4d88ce8ffd7bc452428b235868; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <5db0d252c64e91ba1929c70112352e85dc5751e7; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <79ef8a6c4ec53d327580fd7d2b522cf4f1d05b0c; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <82f51bff393e4c12cf4de553120ca831cfa4ef19; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <ad862f71016ba38039df1c96ed55c0a4314cc183; version=98e4da8ca301e062d79ae168c67e56f3c3de3ce4 <ee1b421c469876544e297ec1090574bd76100247

Published CVSS scores

5.5Canonical UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8kernel.orgCVSS: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

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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