CVE-2026-63812

Filesystem corruption via stale extent-cache metadata

Published Jul 19, 2026 · Updated Jul 19, 2026

Race condition in F2FS in Linux Kernel allows local users to corrupt filesystem metadata through concurrent file activity. The __destroy_extent_node() path sets FI_NO_EXTENT without clearing the largest-extent length or updating the inode folio, leaving stale metadata after extent-tree changes stop. Unprivileged write access to files on a mounted F2FS filesystem is sufficient to orchestrate inode eviction and concurrent writeback, which can disclose data, corrupt block mappings, or crash the filesystem or kernel.

CVSS severity7.8
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in F2FS in Linux Kernel allows local users to corrupt filesystem metadata through concurrent file activity. The __destroy_extent_node() path sets FI_NO_EXTENT without clearing the largest-extent length or updating the inode folio, leaving stale metadata after extent-tree changes stop. Unprivileged write access to files on a mounted F2FS filesystem is sufficient to orchestrate inode eviction and concurrent writeback, which can disclose data, corrupt block mappings, or crash the filesystem or kernel.

The record

CVE
CVE-2026-63812
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-821, T1499
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=0559a0e962aacbb47519e26ee663be04b72dcb92
  2. Affected versionversion=42dd1c91f993431d0b399502479d00e6ad1bca71 <7e4d8f98be63f98856a5176b9188dada6e7ba9ee
  3. Affected versionversion=6.12.88 <6.12.95
  4. Affected versionversion=6.18.30 <6.18.38
  5. Affected versionversion=6.6.140 <6.6.144
  6. Affected versionversion=7.0.7 <7.1
  7. Affected versionversion=7.1
  8. Affected versionversion=ab1eaf9d5c99042f5b0243bf67a06283a4c0757f <58a5deb220bcac4c73bf58954c0845644c997487
  9. Affected versionversion=b0e4395870eb3441ddc959f6710b5f6ca61aff26 <20190e498057997532c7f186d081011f18e0a462
  10. Affected versionversion=ed78aeebef05212ef7dca93bd931e4eff67c113f <1f70ddb28a3c71df124da5fa4040c808116d6bb9
  11. Affected versionversion=ed78aeebef05212ef7dca93bd931e4eff67c113f <edf12cbeeeabe799bd2ee21fdb5c336cce6fbad7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0559a0e962aacbb47519e26ee663be04b72dcb92; version=42dd1c91f993431d0b399502479d00e6ad1bca71 <7e4d8f98be63f98856a5176b9188dada6e7ba9ee; version=6.12.88 <6.12.95; version=6.18.30 <6.18.38; version=6.6.140 <6.6.144; version=7.0.7 <7.1; version=7.1; version=ab1eaf9d5c99042f5b0243bf67a06283a4c0757f <58a5deb220bcac4c73bf58954c0845644c997487; version=b0e4395870eb3441ddc959f6710b5f6ca61aff26 <20190e498057997532c7f186d081011f18e0a462; version=ed78aeebef05212ef7dca93bd931e4eff67c113f <1f70ddb28a3c71df124da5fa4040c808116d6bb9; version=ed78aeebef05212ef7dca93bd931e4eff67c113f <edf12cbeeeabe799bd2ee21fdb5c336cce6fbad7

Published CVSS scores

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

CWE-821Incorrect Synchronization
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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