CVE-2024-26773

Filesystem disruption via corrupted-group block allocation

Published Apr 3, 2024 · Updated Aug 5, 2026

A race condition in the ext4 allocator in Linux allows local users to worsen block-bitmap corruption during allocation. Between ext4_mb_good_group and ext4_mb_try_best_found, the allocator releases the group lock and later uses ac_b_ex without rechecking whether the group bitmap was marked corrupt. Exploitation requires local low-privileged access and corruption during that unlock gap; further allocation can worsen filesystem damage and interrupt availability.

CVSS severity5.5
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A race condition in the ext4 allocator in Linux allows local users to worsen block-bitmap corruption during allocation. Between ext4_mb_good_group and ext4_mb_try_best_found, the allocator releases the group lock and later uses ac_b_ex without rechecking whether the group bitmap was marked corrupt. Exploitation requires local low-privileged access and corruption during that unlock gap; further allocation can worsen filesystem damage and interrupt availability.

The record

CVE
CVE-2024-26773
Published
Apr 3, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 3, 2024CVE 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=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <0184747b552d6b5a14db3b7fcc3b792ce64dedd1
  2. Affected versionversion=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <21f8cfe79f776287459343e9cfa6055af61328ea
  3. Affected versionversion=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <260fc96283c0f594de18a1b045faf6d8fb42874d
  4. Affected versionversion=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <4530b3660d396a646aad91a787b6ab37cf604b53
  5. Affected versionversion=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <4c21fa60a6f4606f6214a38f50612b17b2f738f5
  6. Affected versionversion=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <927794a02169778c9c2e7b25c768ab3ea8c1dc03
  7. Affected versionversion=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <a2576ae9a35c078e488f2c573e9e6821d651fbbe
  8. Affected versionversion=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <f97e75fa4e12b0aa0224e83fcbda8853ac2adf36
  9. Affected versionversion=3.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <0184747b552d6b5a14db3b7fcc3b792ce64dedd1; version=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <21f8cfe79f776287459343e9cfa6055af61328ea; version=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <260fc96283c0f594de18a1b045faf6d8fb42874d; version=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <4530b3660d396a646aad91a787b6ab37cf604b53; version=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <4c21fa60a6f4606f6214a38f50612b17b2f738f5; version=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <927794a02169778c9c2e7b25c768ab3ea8c1dc03; version=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <a2576ae9a35c078e488f2c573e9e6821d651fbbe; version=163a203ddb36c36d4a1c942aececda0cc8d06aa7 <f97e75fa4e12b0aa0224e83fcbda8853ac2adf36; version=3.12

Published CVSS scores

5.5NIST NVDCVSS: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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