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Vulnerabilities/CVE-2026-52955Public Intelligence Dossier
Source: linux · Limited verification•Last verified: •Collection Degraded
CVE-2026-52955Unknown / EvaluatingCRITICAL (raw)CVSS 9.8CWE-125

In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential out-of-bounds access in crush_decode() A message of type CEPH_MSG_OSD_MAP containing a crush map with at least one bucket has two fields holding the bucket algorithm

Published: 24 Jun 2026•Last updated: 16 Oct 2026, 09:48 PM IST•Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Dossier completeness: source-provided sections 2 / 3 · rule guidance available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
9.8CRITICAL (raw)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Metric source416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS probability
0.4%0.004
Percentile30th
Weakness type
CWE-125
CWE-131
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential out-of-bounds access in crush_decode() A message of type CEPH_MSG_OSD_MAP containing a crush map with at least one bucket has two fields holding the bucket algorithm. If the values in these two fields differ, an out-of-bounds access can occur. This is the case because the first algorithm field (alg) is used to allocate the correct amount of memory for a bucket of this type, while the second algorithm field inside the bucket (b->alg) is used in the subsequent processing. This patch fixes the issue by adding a check that compares alg and b->alg and aborts the processing in case they differ. Furthermore, b->alg is set to 0 in this case, because the destruction of the crush map also uses this field to determine the bucket type, which can again result in an out-of-bounds access when trying to free the memory pointed to by the fields of the bucket. To correctly free the memory allocated for the bucket in such a case, the corresponding call to kfree is moved from the algorithm-specific crush_destroy_bucket functions to the generic crush_destroy_bucket().

SOC priority

High Severity / Review

Actively exploited

Unknown

Publicly disclosed

Unknown

Risk basis: SOC ecosystem technology relevance; CRITICAL severity; Critical CVSS without confirmed KEV exploitation

Affected Products & Remediation

1 source-backed product
Affected products and versions (source)
  • linux linux kernel · >= 2.6.34.1 < 5.10.258; >= 5.11 < 5.15.209; >= 5.16 < 6.1.175; >= 6.2 < 6.6.141; >= 6.7 < 6.12.91; >= 6.13 < 6.18.33; >= 6.19 < 7.0.10; 2.6.34; 7.1 · NVD CPE · Source
Recorded patch / KBNot provided by source

Vendor or catalog guidance (source)

Not provided by source

Known exploitation (source facts)

Only what a source states. Unknown means no source has said either way; it is not "not exploited".

CISA KEV
Unknown
Exploited (source statement)
Unknown
Publicly disclosed (source)
Unknown

Suggested hunting (rule-based inference)

SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.

Matched network-unauthenticated (CVSS AV:N, CVSS PR:N, CVSS UI:N)

Exposure

  1. Identify devices reporting this CVE and note which expose the affected service to untrusted networks.Telemetry: DeviceTvmSoftwareVulnerabilities · A network-reachable, no-privilege vector makes internet-facing instances the first exposure question. · Rule network-unauthenticated

Exploitation evidence

  1. Review inbound connections to the affected service from unexpected sources since the advisory date.Telemetry: DeviceNetworkEvents · Hunting hypothesis from the CVSS vector; it does not show that exploitation occurred. · Rule network-unauthenticated

Response

  1. Confirm the source-stated update is installed and the CVE is no longer reported.Telemetry: DeviceTvmSoftwareVulnerabilities · A follow-up inventory check verifies remediation. · Rule network-unauthenticated

CISA KEV Record

CISA KEV status was not determined for this record.

Change History & Source Data

— No recorded material change

CNA / source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Record status · verification
UPDATED · NVD API
CPE
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:2.6.34:-:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:2.6.34:rc2:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:2.6.34:rc3:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:2.6.34:rc4:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:2.6.34:rc5:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:2.6.34:rc6:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:2.6.34:rc7:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*

Evidence & Provenance

3 public sources
git.kernel.orgSource recordnvd.nist.govSource recordgit.kernel.orgSource record

Linked by the query's stored exact CVE association. Review required tables and validation status before use.

Detection Hunting Query
Target: DeviceTvmSoftwareVulnerabilities•Defender XDR
Detect endpoints exposed to CVE-2026-52955
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2026-52955
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-52955"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc
Schema Checked · Not runtime validatedSource: SecOps Signal deterministic template · Limited verificationStatic screening: Passed structure and schema checks; tenant execution is not verified.
Open KQL Library
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Correlated briefings

SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.