CVE-2026-52955Network attack vector

Out-of-bounds kernel access via mismatched bucket algorithms

Published Jun 24, 2026 · Updated Jun 24, 2026

Out-of-bounds access in Linux Kernel libceph allows remote attackers to corrupt kernel memory via a malformed Ceph OSD map. crush_decode() allocates a bucket using the outer alg field but processes and destroys it according to the unchecked inner b->alg field. Reachability requires an affected host to use the kernel Ceph client and accept the crafted map; Red Hat instead assesses a local, low-privileged, availability-only path.

CVSS severity9.8
Critical
EPSS probability0.38%
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 access in Linux Kernel libceph allows remote attackers to corrupt kernel memory via a malformed Ceph OSD map. crush_decode() allocates a bucket using the outer alg field but processes and destroys it according to the unchecked inner b->alg field. Reachability requires an affected host to use the kernel Ceph client and accept the crafted map; Red Hat instead assesses a local, low-privileged, availability-only path.

The record

CVE
CVE-2026-52955
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125, CWE-131
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <5.10.258
  2. Affected versionversion=0 <5.15.209
  3. Affected versionversion=0 <6.1.175
  4. Affected versionversion=0 <6.12.91
  5. Affected versionversion=0 <6.18.33
  6. Affected versionversion=0 <6.6.141
  7. Affected versionversion=0 <7.0.10
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0f3604cbe4df14c5e58288ac9f57511e726a222d
  9. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3f42508191e129ee6b5ea96578d5cab14f2a013a
  10. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4c79fc2d598694bda845b46229c9d48b65042970
  11. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6e70ef53e818c53eab28d7b0026b7fd03dddaba5
  12. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5
  13. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ea0d42137f0c06da71e37ffc647aab4c5309599a
  14. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ebe76d58a48a48031b98543d86c4cd30a825b622
  15. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fb176a99e4c1a5a8448a83d83d3606203ba81faa

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <5.10.258; version=0 <5.15.209; version=0 <6.1.175; version=0 <6.12.91; version=0 <6.18.33; version=0 <6.6.141; version=0 <7.0.10; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0f3604cbe4df14c5e58288ac9f57511e726a222d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3f42508191e129ee6b5ea96578d5cab14f2a013a; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4c79fc2d598694bda845b46229c9d48b65042970; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6e70ef53e818c53eab28d7b0026b7fd03dddaba5; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ea0d42137f0c06da71e37ffc647aab4c5309599a; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ebe76d58a48a48031b98543d86c4cd30a825b622; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fb176a99e4c1a5a8448a83d83d3606203ba81faa

Published CVSS scores

4.7Red Hat SADPCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
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-125Out-of-bounds Read
CWE-131Incorrect Calculation of Buffer Size

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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