CVE-2026-63819

Kernel panic via unchecked F2FS node footer

Published Jul 19, 2026 · Updated Jul 19, 2026

F2FS node validation in Linux Kernel before 6.18.39 and before 7.1.3 allows local users to trigger a kernel panic. f2fs_get_node_folio_ra accepts a direct node whose footer repeats the inode and node identifiers, causing f2fs_do_truncate_blocks to derive a negative block count. An unprivileged local user can reach the truncate path on an already mounted crafted F2FS volume, but mounting the image requires elevated privileges.

CVSS severity7.8
High
EPSS probability0.17%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

F2FS node validation in Linux Kernel before 6.18.39 and before 7.1.3 allows local users to trigger a kernel panic. f2fs_get_node_folio_ra accepts a direct node whose footer repeats the inode and node identifiers, causing f2fs_do_truncate_blocks to derive a negative block count. An unprivileged local user can reach the truncate path on an already mounted crafted F2FS volume, but mounting the image requires elevated privileges.

The record

CVE
CVE-2026-63819
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-823, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=0 <6.18.39
  2. Affected versionversion=0 <7.1.3
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0cc21c1ffe15b4156b0bf744f32fd1faef0b7c73
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <406c28af75123432d38cf9bbaa6f1476f7b14770
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8712353ed80f87271d732297567dcdbe4b84e8c7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <6.18.39; version=0 <7.1.3; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0cc21c1ffe15b4156b0bf744f32fd1faef0b7c73; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <406c28af75123432d38cf9bbaa6f1476f7b14770; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8712353ed80f87271d732297567dcdbe4b84e8c7

Published CVSS scores

7.8Linux kernel CVE teamCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-823Use of Out-of-range Pointer Offset
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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