CVE-2026-74349

Out-of-range disk discard via FITRIM underflow

Published Aug 15, 2026 · Updated Aug 15, 2026

Integer underflow in the OCFS2 filesystem in Linux allows local users to discard data beyond a requested FITRIM range. ocfs2_trim_mainbm() validates the range against the block size, rounds a sub-cluster length to zero, and then underflows its end and remaining-length arithmetic. Exploitation requires local low-privileged access and an OCFS2 filesystem whose cluster size exceeds its block size, risking data corruption and service interruption.

CVSS severity7.1
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in the OCFS2 filesystem in Linux allows local users to discard data beyond a requested FITRIM range. ocfs2_trim_mainbm() validates the range against the block size, rounds a sub-cluster length to zero, and then underflows its end and remaining-length arithmetic. Exploitation requires local low-privileged access and an OCFS2 filesystem whose cluster size exceeds its block size, risking data corruption and service interruption.

The record

CVE
CVE-2026-74349
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-191, CWE-190, T1485
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=3.14
  2. Affected versionversion=aa89762c54800208d5afdcd8e6bf124818f17fe0 <06c0a0431b9856506fcd9b2c1b0c6136567d756d
  3. Affected versionversion=aa89762c54800208d5afdcd8e6bf124818f17fe0 <2c13e02592b918be7725ab5965e01ef4e46c4b57
  4. Affected versionversion=aa89762c54800208d5afdcd8e6bf124818f17fe0 <346314bb0cc2fc52b50b73d6ecc62e0217455c2e
  5. Affected versionversion=aa89762c54800208d5afdcd8e6bf124818f17fe0 <3fa7139b5f42731a61f78c42433adae13f9adc21
  6. Affected versionversion=aa89762c54800208d5afdcd8e6bf124818f17fe0 <441abb77222f155e8d931dbabb465466db01cfd7
  7. Affected versionversion=aa89762c54800208d5afdcd8e6bf124818f17fe0 <ca1afd88f5eaaff9168e1466e5401385edf59543
  8. Affected versionversion=aa89762c54800208d5afdcd8e6bf124818f17fe0 <d903d59c0315f59bdf0214b4f13d71c9feb2c45c
  9. Affected versionversion=aa89762c54800208d5afdcd8e6bf124818f17fe0 <e652d0f5108e447b22da4249bcd23dd1b63c73dd

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.14; version=aa89762c54800208d5afdcd8e6bf124818f17fe0 <06c0a0431b9856506fcd9b2c1b0c6136567d756d; version=aa89762c54800208d5afdcd8e6bf124818f17fe0 <2c13e02592b918be7725ab5965e01ef4e46c4b57; version=aa89762c54800208d5afdcd8e6bf124818f17fe0 <346314bb0cc2fc52b50b73d6ecc62e0217455c2e; version=aa89762c54800208d5afdcd8e6bf124818f17fe0 <3fa7139b5f42731a61f78c42433adae13f9adc21; version=aa89762c54800208d5afdcd8e6bf124818f17fe0 <441abb77222f155e8d931dbabb465466db01cfd7; version=aa89762c54800208d5afdcd8e6bf124818f17fe0 <ca1afd88f5eaaff9168e1466e5401385edf59543; version=aa89762c54800208d5afdcd8e6bf124818f17fe0 <d903d59c0315f59bdf0214b4f13d71c9feb2c45c; version=aa89762c54800208d5afdcd8e6bf124818f17fe0 <e652d0f5108e447b22da4249bcd23dd1b63c73dd

Published CVSS scores

6.0Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
7.1NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
5.5OracleCVSS: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

CWE-191Integer Underflow (Wrap or Wraparound)
CWE-190Integer Overflow or Wraparound
T1485Data Destruction

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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