CVE-2025-40077

Service interruption via F2FS page-offset overflow

Published Oct 28, 2025 · Updated Oct 28, 2025

Integer overflow in Linux F2FS allows local users to interrupt service during truncation of a compressed file on an F2FS volume. In f2fs_truncate_partial_cluster(), folio->index is left-shifted by PAGE_SHIFT while still typed as pgoff_t, so large page indexes overflow before assignment to the loff_t start offset. Local access sufficient to truncate a compressed F2FS inode is required; the published assessment limits impact to availability, with no confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Linux F2FS allows local users to interrupt service during truncation of a compressed file on an F2FS volume. In f2fs_truncate_partial_cluster(), folio->index is left-shifted by PAGE_SHIFT while still typed as pgoff_t, so large page indexes overflow before assignment to the loff_t start offset. Local access sufficient to truncate a compressed F2FS inode is required; the published assessment limits impact to availability, with no confidentiality or integrity impact.

The record

CVE
CVE-2025-40077
Published
Oct 28, 2025
Updated
Oct 28, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 2025Record 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=3265d3db1f16395cfc6b8ea9b31b4001d98d05ef <0fe1c6bec54ea68ed8c987b3890f2296364e77bb
  2. Affected versionversion=3265d3db1f16395cfc6b8ea9b31b4001d98d05ef <57d3381dfb97ff73ddd18601017fec21cca80985
  3. Affected versionversion=5.8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3265d3db1f16395cfc6b8ea9b31b4001d98d05ef <0fe1c6bec54ea68ed8c987b3890f2296364e77bb; version=3265d3db1f16395cfc6b8ea9b31b4001d98d05ef <57d3381dfb97ff73ddd18601017fec21cca80985; version=5.8

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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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