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CVE Record

CVE-2026-43125: dlm: validate length in dlm_search_rsb_tree

In the Linux kernel, the following vulnerability has been resolved: dlm: validate length in dlm_search_rsb_tree The len parameter in dlm_dump_rsb_name() is not validated and comes from network messages. When it exceeds DLM_RESNAME_MAXLEN, it can cause out-of-bounds write in dlm_search_rsb_tree(). Add length validation to prevent potential buffer overflow.

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

CVE-2026-43125 is a Linux kernel DLM flaw where a network-supplied length value is not checked. On affected systems using DLM, this can lead to a kernel buffer overflow with potential full confidentiality, integrity, and availability impact. The sources show fixes and Red Hat advisories, but do not show confirmed active exploitation.

Executive priority

Prioritize remediation for clustered Linux environments and any system where DLM may be reachable over a network. The vulnerability is critical by CVSS and affects kernel code, but urgency should be risk-ranked by confirmed DLM use and vendor package status.

Technical view

The issue is in Linux kernel DLM handling around dlm_dump_rsb_name() and dlm_search_rsb_tree(). A len value from network messages can exceed DLM_RESNAME_MAXLEN, causing an out-of-bounds write. The CVSS 3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, score 9.8.

Likely exposure

Exposure is most likely on Linux systems running affected kernels with DLM enabled or used for cluster locking. Systems not using DLM are less likely exposed, but should still validate kernel status because affected-version data in the bundle is broad and distribution-specific.

Exploitation context

The CVSS vector indicates possible network attack surface without credentials or user interaction. However, KEV is false and the provided sources do not cite active exploitation or public exploit availability. Treat this as urgent because kernel memory corruption can have severe outcomes.

Researcher notes

Evidence supports a length-validation bug fixed in Linux stable commits. The source bundle does not provide exploit details, affected distribution matrices beyond Red Hat references, or proof of exploitation. Avoid assuming impact on systems where DLM is absent or unreachable.

Mitigation direction

  • Apply vendor kernel updates that include the referenced DLM length-validation fix.
  • Use Red Hat RHSA or your distribution advisory to identify fixed package versions.
  • Restrict DLM and cluster traffic to trusted cluster nodes only.
  • Disable DLM where it is not required for the system role.
  • Reboot into the fixed kernel after patching.
  • Continue monitoring vendor guidance for distribution-specific status.

Validation and detection

  • Inventory Linux kernels and map them to vendor CVE advisories.
  • Check whether DLM is loaded, enabled, or required by cluster services.
  • Confirm the installed kernel includes a fix or vendor backport for this CVE.
  • Review firewall rules limiting DLM or cluster traffic to trusted nodes.
  • Verify patched systems have rebooted into the updated kernel.
Prepared
Confidence
medium
Sources
10

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · low confidence lookup

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cve · low confidence lookup

CVE-2026-43125 mapping review

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
1ADP providers
19Source links

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Linux
7CVSS 3.1HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H15.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2026-43125Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

redhat-SADPkernel: dlm: validate length in dlm_search_rsb_tree
other:Red Hat severity ratingcvssV3_1
  • 2026-05-06T00:00:00.000Z: Reported to Red Hat.
  • 2026-05-06T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux7210cb7a72a22303cdb225bd1aea28697a17bbae, 7210cb7a72a22303cdb225bd1aea28697a17bbae, 7210cb7a72a22303cdb225bd1aea28697a17bbae, 7210cb7a72a22303cdb225bd1aea28697a17bbaeunaffected
LinuxLinux3.4, 0, 6.12.75, 6.18.16, 6.19.6, 7.0affected
Weakness

CWE details

CWE-130

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-130 · source CWE mapping

Improper Handling of Length Parameter Inconsistency

Improper Handling of Length Parameter Inconsistency represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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