CVE-2026-53309Network attack vector

Out-of-bounds read via inclusive region loop

Published Jun 26, 2026 · Updated Jun 26, 2026

Out-of-bounds read in Linux Kernel OCFS2 DLM allows remote attackers to trigger a one-entry over-read during region matching. In dlm_match_regions(), the local-to-remote loop permits j to equal qr_numregions and passes the one-past-end qr_regions entry to memcmp. The affected path processes DLM region comparisons; published records do not show that bytes are returned, memory is disclosed, or the kernel crashes.

CVSS severity9.8
Critical
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux Kernel OCFS2 DLM allows remote attackers to trigger a one-entry over-read during region matching. In dlm_match_regions(), the local-to-remote loop permits j to equal qr_numregions and passes the one-past-end qr_regions entry to memcmp. The affected path processes DLM region comparisons; published records do not show that bytes are returned, memory is disclosed, or the kernel crashes.

The record

CVE
CVE-2026-53309
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-193
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 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=2.6.37
  2. Affected versionversion=ea2034416b54700e30371f2ad6517cbb94674083 <01b61e8dda9b0fdb0d4cda43de25f4e390554d7b
  3. Affected versionversion=ea2034416b54700e30371f2ad6517cbb94674083 <1fb7f356547d9688822315cd2b205ff0bd5429b4
  4. Affected versionversion=ea2034416b54700e30371f2ad6517cbb94674083 <2a0673836f019e7c032acbf48d022d5ccf02a845
  5. Affected versionversion=ea2034416b54700e30371f2ad6517cbb94674083 <426cd8eedac89b86148d4478990eeef16e8a2520
  6. Affected versionversion=ea2034416b54700e30371f2ad6517cbb94674083 <760ab35040aca8399021fdb9ff1db1089feb7194
  7. Affected versionversion=ea2034416b54700e30371f2ad6517cbb94674083 <819d8ebad3200a53de99bd7e297bc428e41ced54
  8. Affected versionversion=ea2034416b54700e30371f2ad6517cbb94674083 <c60a2710b73838d250cda57344c049b89abc5d52
  9. Affected versionversion=ea2034416b54700e30371f2ad6517cbb94674083 <d5403ae28085761d58b555645bc7d5feadb10073

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.37; version=ea2034416b54700e30371f2ad6517cbb94674083 <01b61e8dda9b0fdb0d4cda43de25f4e390554d7b; version=ea2034416b54700e30371f2ad6517cbb94674083 <1fb7f356547d9688822315cd2b205ff0bd5429b4; version=ea2034416b54700e30371f2ad6517cbb94674083 <2a0673836f019e7c032acbf48d022d5ccf02a845; version=ea2034416b54700e30371f2ad6517cbb94674083 <426cd8eedac89b86148d4478990eeef16e8a2520; version=ea2034416b54700e30371f2ad6517cbb94674083 <760ab35040aca8399021fdb9ff1db1089feb7194; version=ea2034416b54700e30371f2ad6517cbb94674083 <819d8ebad3200a53de99bd7e297bc428e41ced54; version=ea2034416b54700e30371f2ad6517cbb94674083 <c60a2710b73838d250cda57344c049b89abc5d52; version=ea2034416b54700e30371f2ad6517cbb94674083 <d5403ae28085761d58b555645bc7d5feadb10073

Published CVSS scores

9.8kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-193Off-by-one Error

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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